@Statistics — Returns statistics about the usage of the VoltDB database.
@Statistics String component, Integer delta-flag
The @Statistics system procedure returns information about the VoltDB database. The first argument, component, specifies what aspect of VoltDB to return statistics about. The second argument, delta-flag, specifies whether statistics are reported from when the database started or since the last call to @Statistics where the flag was set.
Some components report statistics at the moment, collected when you make the procedure call. While other components report statistics over time. For cumulative components, if the delta flag is set to zero, the system procedure returns statistics since the database started. If the delta flag is non-zero, the system procedure returns statistics for the interval since the last time @Statistics was called with a non-zero flag. (If @Statistics has not been called with a non-zero flag before, the first call with the flag set returns statistics since startup.) The statistics that are affected by the delta flag are EXPORT, GC, IDLETIME, IMPORT, INITIATOR, IOSTATS, PLANNER, QUEUE, TTL, and the procedure statistics (PROCEDURE, PROCEDUREDETAIL, PROCEDUREINPUT, PROCEDUREOUTPUT, and PROCEDUREPROFILE).
Note that in a cluster with K-safety, if a node fails, the statistics reported by this procedure are reset to zero for the node when it rejoins the cluster.
The following are the allowable values of component:
Returns information about the progress of command logging, including the number of segment files in use and the amount of command log data waiting to be written to disk.
Returns information about the amount of CPU used by each VoltDB server process. CPU usage is returned as a number between 0 and 100 representing the amount of CPU used by the VoltDB process out of the total CPU available for that server.
Returns information about the status of database replication on a DR consumer, including the status and data replication rate of each partition. This information is available only if the database is licensed for database replication and operating as a passive DR replica or an active XDCR database.
Returns information about the status of database replication on a producer database, including how much data is waiting to be sent to the consumer. This information is available only if the database is licensed for database replication and is operating as a passive master or an active XDCR database.
Returns information about the current state of database replication (DR), including the role of the cluster (master, replica, or XDCR) and whether DR has started, is running, stopped, or been disabled.
Returns statistics on the export streams and targets, including how many records have be written, how many are pending, and the status of the export connection.
Returns statistics on Java garbage collection associated with the server process on each host.
Returns statistics on how busy the partitions are. For each execution site, the results provide a minimum, maximum, and average amount of time the site waited without any transactions to process, as well as the overall percentage of time the site was waiting (that is, the partition was "idle").
Returns statistics on the import streams, including how many import transactions have succeeded, failed, and been retried and how many rows have been read but not applied yet.
Returns information about the indexes in the database, including the number of keys for each index and the estimated amount of memory used to store those keys. Separate information is returned for each partition in the database.
Returns information on the number of procedure invocations for each stored procedure (including system and import procedures). The count of invocations is reported for each connection to the database.
Returns information on the number of messages and amount of data (in bytes) sent to and from each connection to the database.
Returns statistics on the latency of transactions. The information reports on median, percentage (99% through 99.999%), and maximum latency over the most recent five second sampling period.
Returns information about the number of outstanding requests per client. You can use this information to determine how much work is waiting in the execution queues.
Returns the same information as MEMORY, INITIATOR, PROCEDURE, IOSTATS, TABLE, INDEX, IDLETIME, QUEUE, and CPU, except all in a single procedure call.
Returns statistics on the use of memory for each node in the cluster. MEMORY statistics include the current resident set size (RSS) of the VoltDB server process; the amount of memory used for Java temporary storage, database tables, indexes, and string (including varbinary) storage; as well as other information.
Returns information on the number of unique partitions in the cluster. The VoltDB cluster creates multiple partitions based on the number of servers and the number of sites per host requested. So, for example, a 2 node cluster with 4 sites per host will have 8 partitions. However, when you define a cluster with K-safety, there are duplicate partitions. PARTITIONCOUNT only reports the number of unique partitions available in the cluster.
Returns information on the use of cached plans within each partition. Queries in stored procedures are planned when the procedure is declared in the schema. However, ad hoc queries must be planned at runtime. To improve performance, VoltDB caches plans for ad hoc queries so they can be reused when a similar query is encountered later. There are two caches: the level 1 cache performs exact matches on queries and the level 2 cache parameterizes constants so it can match queries with the same plan but different input. The planner statistics provide information about the size of each cache, how frequently it is used, and the minimum, maximum, and average execution time of ad hoc queries as a result.
Returns information on the usage of stored procedures for each site within the database cluster sorted by partition. The information includes the name of the procedure, the number of invocations (for each site), and selected performance information on minimum, maximum, and average execution time.
Returns detailed performance information about the individual statements within each stored procedure. PROCEDUREDETAIL returns information for each statement in each procedure, grouped by site and partition within the database cluster. The information includes the name of the procedure, the name of the statement, the number of invocations (for each site), and selected performance information on minimum, maximum, and average execution time.
Returns summary information on the size of the input data submitted with stored procedure invocations. PROCEDUREINPUT uses information from PROCEDURE, except it focuses on the input parameters and aggregates data for the entire cluster.
Returns summary information on the size of the result sets returned by stored procedure invocations. PROCEDUREOUTPUT uses information from PROCEDURE, except it focuses on the result sets and aggregates data for the entire cluster.
Returns summary information on the usage of stored procedures averaged across all partitions in the cluster. The information from PROCEDUREPROFILE is similar to the information from PROCEDURE, except it focuses on the performance of the individual procedures rather than on procedures by partition. The weighted average across partitions is helpful for determining which stored procedures the application is spending most of its time in.
Returns statistics on the number of tasks in each partition's process queue and the average and maximum time tasks were waiting in the queue.
Returns information on the current progress of rebalancing on the cluster. Rebalancing occurs when one or more nodes are added "on the fly" to an elastic cluster. If no rebalancing is occurring, no data is returned. During a rebalance, this selector returns information about the speed of migration of the data, the latency of rebalance tasks, and the estimated time until completion. All rebalance statistics are cumulative for the current rebalance activity.
Returns information about the individual files of up to ten recent snapshots performed by the database. The results include the directory path and prefix for the snapshot, when it occurred, how long it took, and whether the snapshot was completed successfully or not. The results report on both native and CSV snapshots, as well as manual, automated, and command log snapshots. Note that this selector does not tell you whether the snapshot files still exist, only that the snapshot was performed. Use the @SnapshotScan procedure to determine what snapshots are available.
Returns information about up to ten recent snapshots performed by the database. Unlike SNAPSHOTSTATUS, which reports on individual files, SNAPSHOTSUMMARY provides a one row summary for each snapshot. The results include the directory path and prefix, when the snapshot started, how long it took, and whether the snapshot was completed successfully or not. If the snapshot is still in progress, the results include the percentage complete. Note that this selector does not tell you whether the snapshot files still exist, only that the snapshot was started. Use the @SnapshotScan procedure to determine what snapshot files are available.
Returns information about the database tables, including the number of rows per site for each table. This information can be useful for seeing how well the rows are distributed across the cluster for partitioned tables.
Returns information about scheduled tasks and their current status. There are separate queues for the task schedulers and the task procedures, which run on the standard transactional partition queues. The TASK selector reports on both. Separate selectors for TASK_SCHEDULER and TASK_PROCEDURE report on a corresponding subset of the columns.
Returns statistics about the queues for outbound topics (that is, data fetched by consumers) including throughput, offsets, and retention policy, as well as how much data is currently stored on disk.
Returns information about the processing of expired data in "time to live" (TTL) tables, including how recently and how many records have been deleted.
Note that INITIATOR and PROCEDURE report information on both user-declared stored procedures and system procedures. These include certain system procedures that are used internally by VoltDB and are not intended to be called by client applications. Only the system procedures documented in this appendix are intended for client invocation.
Returns different VoltTables depending on which component is requested. The following tables identify the structure of the return values for each component. (Note that the MANAGEMENT component returns seven VoltTables.)
COMMANDLOG — Returns a row for every server in the cluster.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
OUTSTANDING_BYTES | BIGINT | The size, in bytes, of pending command log data. That is, data for transactions that have been initiated but the log has yet to be written to disk. For synchronous logging, this value is always zero. |
OUTSTANDING_TXNS | BIGINT | The size, in number of transactions, of pending command log data. That is, the number of transactions that have been initiated for which the log has yet to be written to disk. For synchronous logging, this value is always zero. |
IN_USE_SEGMENT_COUNT | INTEGER | The total number of segment files currently in use for command logging. |
SEGMENT_COUNT | INTEGER | The number of segment files allocated, including currently unused segments. |
FSYNC_INTERVAL | INTEGER | The average interval, in milliseconds, between the last 10 fsync system calls. |
CPU — Returns a row for every server in the cluster.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
PERCENT_USED | BIGINT | The percentage of total CPU available used by the database server process. |
DRCONSUMER — Returns two VoltTables. The first table returns a row for every host in the cluster, showing whether a replication snapshot is in progress and if it is, the status of transmission to the consumer.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
CLUSTER_ID | INTEGER | The numeric ID of the current cluster. |
REMOTE_CLUSTER_ID | INTEGER | The numeric ID of the producer cluster. |
STATE | STRING | A text string indicating the current state of replication. Possible values are:
|
REPLICATION_RATE_1M | BIGINT | The average rate of replication over the past minute. The data rate is measured in bytes per second. |
REPLICATION_RATE_5M | BIGINT | The average rate of replication over the past five minutes. The data rate is measured in bytes per second. |
The second table contains information about the replication streams, which consist of a row per partition for each server. The data shows the current state of replication and how much data has been received by the consumer from each producer.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
CLUSTER_ID | INTEGER | The numeric ID of the current cluster. |
REMOTE_CLUSTER_ID | INTEGER | The numeric ID of the producer cluster. |
PARTITION_ID | INTEGER | The numeric ID for the logical partition. |
IS_COVERED | STRING | A text string of "true" or "false" indicating whether this partition is currently connected to and receiving data from a matching partition on the producer cluster. |
COVERING_HOST | STRING | The host name of the server in the producer cluster that is providing DR data to this partition. If IS_COVERED is "false", this field is empty. |
LAST_RECEIVED_TIMESTAMP | TIMESTAMP | The timestamp of the last transaction received from the producer. |
LAST_APPLIED_TIMESTAMP | TIMESTAMP | The timestamp of the last transaction successfully applied to this partition on the consumer. |
IS_PAUSED | STRING | A text string of "true" or "false" indicating whether this partition is paused. A partition "pauses" when the schema of the DR tables on the producer change to no longer match the consumer and all binary logs prior to the change have been processed. |
DUPLICATE_BUFFERS | BIGINT | The number of repeated buffers received after the initial packets were dropped because the queue was full. |
IGNORED_BUFFERS | BIGINT | The number of buffers received but dropped because the queue was full. |
AVAILABLE_BYTES | INTEGER | The number of free bytes left in the DR queue. |
AVAILABLE_BUFFERS | INTEGER | The number of free buffers left in the DR queue. |
CONSUMER_LIMIT_TYPE | STRING | The type of limit on the DR queue. The response is either BYTES or BUFFERS. |
DRPRODUCER — Returns two VoltTables. The first table contains information about the replication streams, which consist of a row per partition for each server. The data shows the current state of replication and how much data is currently queued for each consumer.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
CLUSTER_ID | INTEGER | The numeric ID of the current cluster. |
REMOTE_CLUSTER_ID | INTEGER | The numeric ID of the consumer cluster. |
PARTITION_ID | INTEGER | The numeric ID for the logical partition. |
STREAMTYPE | STRING | The type of stream, which can either be "TRANSACTIONS" or "SNAPSHOT". |
TOTALBYTES | BIGINT | The total number of bytes currently queued for transmission to the replica. |
TOTALBYTESINMEMORY | BIGINT | The total number of bytes of queued data currently held in memory. If the amount of total bytes is larger than the amount in memory, the remainder is kept in overflow storage on disk. |
TOTALBUFFERS | BIGINT | The total number of buffers in this partition currently waiting for acknowledgement from the replica. The partitions buffer the binary logs to reduce overhead and optimize network transfers. |
LASTQUEUEDDRID | BIGINT | The ID of the last transaction queued for transmission to the consumer. |
LASTACKDRID | BIGINT | The ID of the last transaction acknowledged by the consumer. |
LASTQUEUEDTIMESTAMP | TIMESTAMP | The timestamp of the last transaction queued for transmission to the consumer. |
LASTACKTIMESTAMP | TIMESTAMP | The timestamp of the last transaction acknowledged by the consumer. |
ISSYNCED | STRING | A text string indicating whether the database is currently being replicated. If replication has not started, or the overflow capacity has been exceeded (that is, replication has failed), the value of ISSYNCED is "false". If replication is currently in progress, the value is "true". |
MODE | STRING | A text string indicating whether this particular partition is replicating data to the consumer ("NORMAL") or not ("PAUSED"). Only one copy of each logical partition actually sends data during replication. So for clusters with a K-safety value greater than zero, not all physical partitions will report "NORMAL" even when replication is in progress. |
QUEUE_GAP | BIGINT | The number of missing transactions between those already acknowledged by the consumer and the next available for transmission. Under normal operating conditions, this value is zero. |
CONNECTION_STATUS | STRING | A text string indicating whether the connection to the consumer is operational ("UP") or not ("DOWN"). If the connection between the producer and consumer is broken or if the producer does not hear from the consumer for more than 30 seconds, the connection is marked as "DOWN". |
AVAILABLE_BYTES | INTEGER | The number of bytes waiting to be sent to the consumer |
AVAILABLE_BUFFERS | INTEGER | The number of buffers waiting to be sent to the consumer. |
CONSUMER_LIMIT_TYPE | STRING | The type of limit on the DR queue. The response is either BYTES or BUFFERS. |
The second table returns a row for every host in the cluster, showing whether a replication snapshot is in progress and if it is, the status of transmission to the consumer.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
CLUSTER_ID | INTEGER | The numeric ID of the current cluster. |
REMOTE_CLUSTER_ID | INTEGER | The numeric ID of the consumer cluster. |
STATE | STRING | A text string indicating the current state of replication. Possible values are "OFF" (replication is not enabled), "PENDING" (replication is enabled but not occurring), and "ACTIVE" (replication is enabled and a replica database has initiated DR). |
SYNCSNAPSHOTSTATE | STRING | A text string indicating the current state of the synchronization snapshot that begins replication. During normal operation, this value is "NONE" indicating either that replication is not active or that transactions are actively being replicated. If a synchronization snapshot is in progress, this value provides additional information about the specific activity underway. |
ROWSINSYNCSNAPSHOT | BIGINT | Reserved for future use. |
ROWSACKEDFORSYNCSNAPSHOT | BIGINT | Reserved for future use. |
DRROLE — Returns one row per connection showing the current status of DR for that cluster.
Name | Datatype | Description |
---|---|---|
ROLE | STRING | The role of the current cluster in a DR relationship. Possible values are NONE, MASTER, REPLICA, and XDCR. (None indicates that no DR ID is defined and the cluster cannot participate in DR.) |
STATE | STRING | The current state of the DR relationship. Possible values are the following:
Note that if DR stops, issuing the voltadmin dr reset command will return the cluster to the PENDING state. |
REMOTE_CLUSTER_ID | INTEGER | The DR ID of the other DR cluster, or -1 if not available (for example, when DR is disabled or communication has not begun). |
EXPORT — Returns a separate row for each export stream per partition.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
SITE_ID | INTEGER | Numeric ID of the execution site on the host node. |
PARTITION_ID | INTEGER | The numeric ID for the logical partition. |
SOURCE | STRING | The name of the export stream. |
TARGET | STRING | The name of the export target. |
ACTIVE | STRING | Whether this site is currently actively exporting data. For normal export in a K-safe cluster, only one copy of each partition actively exports data at any given time. Possible values for user export are "TRUE" and "FALSE". Note that cross datacenter replication (XDCR) uses the export infrastructure to write the DR conflict logs. In this case, all copies of the partition write the logs and the ACTIVE column is marked as "XDCR" to distinguish it from user-defined export streams. |
TUPLE_COUNT | BIGINT | The total number of records queued to the export target. |
TUPLE_PENDING | BIGINT | The number of records out of TUPLE_COUNT still waiting to be written to or acknowledged by the target. |
LAST_QUEUED_TIMESTAMP | TIMESTAMP | The timestamp when the most recent tuple was added to the export queue for this partition (in milliseconds). |
LAST_ACKED_TIMESTAMP | TIMESTAMP | The timestamp when the last tuple was acknowledged as received by the target (in milliseconds). |
AVERAGE_LATENCY | BIGINT | The average time between when records are inserted and they are acknowledged by the target. |
MAXIMUM_LATENCY | BIGINT | The maximum time between when a record was inserted and it was acknowledged by the target. |
QUEUE_GAP | BIGINT | The number of records missing from the queue for the current stream and partition. |
STATUS | STRING | The current status of the export connection. Possible values are the following:
Note that if the queue is blocked, the voltadmin export release command returns the queue to the ACTIVE state. |
GC — Returns a separate row for each host.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
NEWGEN_GC_COUNT | INTEGER | The number of times "young generation" garbage collection was performed. |
NEWGEN_AVG_GC_TIME | BIGINT | The average time (in milliseconds) taken by young generation collections. |
OLDGEN_GC_COUNT | INTEGER | The number of times "old generation" garbage collection was performed. |
OLDGEN_AVG_GC_TIME | BIGINT | The average time (in milliseconds) taken by old generation collections. |
IDLETIME — Returns a separate row for each execution site and host.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
SITE_ID | INTEGER | Numeric ID of the execution site on the host node. |
COUNT | BIGINT | The number of times the execution site had to wait for a new task (that is, the queue was empty). |
PERCENT | FLOAT | The percentage of time the execution site was waiting for a new task (that is, the site was "idle"). |
AVG | BIGINT | The average amount of time the execution site had to wait for a new task (in microseconds). |
MIN | BIGINT | The minimum amount of time the execution site had to wait for a new task (in nanoseconds). |
MAX | BIGINT | The maximum amount of time the execution site had to wait for a new task (in nanoseconds). |
STDDEV | BIGINT | The standard deviation of the waiting time (in microseconds). |
IMPORT — Returns a separate row for each import stream and each server.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
SITE_ID | INTEGER | Numeric ID of the execution site on the host node. |
IMPORTER_NAME | STRING | The name of the import stream. |
PROCEDURE_NAME | STRING | The name of the stored procedure invoked by the import stream to insert the incoming data. |
SUCCESSES | BIGINT | The number of import transactions that succeeded. |
FAILURES | BIGINT | The number of import transactions that failed. |
OUTSTANDING_REQUESTS | BIGINT | The number of records read from the import stream and waiting to be inserted into the database. |
RETRIES | BIGINT | The number of attempts to replay failed transactions. |
INDEX — Returns a row for every index in every execution site.
Name | Datatype | Description | ||
---|---|---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). | ||
HOST_ID | INTEGER | Numeric ID for the host node. | ||
HOSTNAME | STRING | Server name of the host node. | ||
SITE_ID | INTEGER | Numeric ID of the execution site on the host node. | ||
PARTITION_ID | BIGINT | The numeric ID for the logical partition that this site represents. When using a K value greater than zero, there are multiple copies of each logical partition. | ||
INDEX_NAME | STRING | The name of the index. | ||
TABLE_NAME | STRING | The name of the database table to which the index applies. | ||
INDEX_TYPE | STRING | A text string identifying whether the index is unique or not. Possible values include the following:
| ||
IS_UNIQUE | TINYINT | A byte value specifying whether the index is unique (1) or not (0). | ||
IS_COUNTABLE | TINYINT | A byte value specifying whether the index maintains a counter to optimize COUNT(*) queries. | ||
ENTRY_COUNT | BIGINT | The number of index entries currently in the partition. | ||
MEMORY_ESTIMATE | BIGINT | The estimated amount of memory (in kilobytes) consumed by the current index entries. |
INITIATOR — Returns a separate row for each connection and the stored procedures initiated by that connection.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
SITE_ID | INTEGER | Numeric ID of the execution site on the host node. |
CONNECTION_ID | BIGINT | Numeric ID of the client connection invoking the procedure. |
CONNECTION_HOSTNAME | STRING | The server name of the node from which the client connection originates. In the case of import procedures, the name of the importer is reported here. |
PROCEDURE_NAME | STRING | The name of the stored procedure. If import is enabled, import procedures are included as well. |
INVOCATIONS | BIGINT | The number of times the stored procedure has been invoked by this connection on this host node. |
AVG_EXECUTION_TIME | INTEGER | The average length of time (in milliseconds) it took to execute the stored procedure. |
MIN_EXECUTION_TIME | INTEGER | The minimum length of time (in milliseconds) it took to execute the stored procedure. |
MAX_EXECUTION_TIME | INTEGER | The maximum length of time (in milliseconds) it took to execute the stored procedure. |
ABORTS | BIGINT | The number of times the procedure was aborted. |
FAILURES | BIGINT | The number of times the procedure failed unexpectedly. (As opposed to user aborts or expected errors, such as constraint violations.) |
IOSTATS — Returns one row for every client connection on the cluster.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
CONNECTION_ID | BIGINT | Numeric ID of the client connection invoking the procedure. |
CONNECTION_HOSTNAME | STRING | The server name of the node from which the client connection originates. |
BYTES_READ | BIGINT | The number of bytes of data sent from the client to the host. |
MESSAGES_READ | BIGINT | The number of individual messages sent from the client to the host. |
BYTES_WRITTEN | BIGINT | The number of bytes of data sent from the host to the client. |
MESSAGES_WRITTEN | BIGINT | The number of individual messages sent from the host to the client. |
LATENCY — Returns a row for every server in the cluster.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp, in milliseconds, when the data was collected (not when the call was processed). If two calls to this selector return the same timestamp, the data being returned is identical. |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
INTERVAL | INTEGER | The length of the measurement interval, in milliseconds. The interval is five seconds (5000). |
COUNT | INTEGER | The total number of transactions during the interval. |
TPS | INTEGER | The number of transactions per second during the interval. |
P50 | BIGINT | The 50th percentile latency, in microseconds. This value measures the median latency. |
P95 | BIGINT | The 95h percentile latency, in microseconds. |
P99 | BIGINT | The 99th percentile latency, in microseconds. |
P99.9 | BIGINT | The 99.9th percentile latency, in microseconds. |
P99.99 | BIGINT | The 99.99th percentile latency, in microseconds. |
P99.999 | BIGINT | The 99.999th percentile latency, in microseconds. |
MAX | BIGINT | The maximum latency during the interval, in microseconds. |
LIVECLIENTS — Returns a row for every client connection currently active on the cluster.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
CONNECTION_ID | BIGINT | Numeric ID of the client connection invoking the procedure. |
CLIENT_HOSTNAME | STRING | The server name of the node from which the client connection originates. |
ADMIN | TINYINT | A byte value specifying whether the connection is to the client port (0) or the admin port (1). |
OUTSTANDING_REQUEST_BYTES | BIGINT | The number of bytes of data sent from the client currently pending on the host. |
OUTSTANDING_RESPONSE_MESSAGES | BIGINT | The number of messages on the host queue waiting to be retrieved by the client. |
OUTSTANDING_TRANSACTIONS | BIGINT | The number of transactions (that is, stored procedures) initiated on behalf of the client that have yet to be completed. |
MEMORY — Returns a row for every server in the cluster.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
RSS | INTEGER | The current resident set size. That is, the total amount of memory allocated to the VoltDB processes on the server. |
JAVAUSED | INTEGER | The amount of memory (in kilobytes) allocated by Java and currently in use by VoltDB. |
JAVAUNUSED | INTEGER | The amount of memory (in kilobytes) allocated by Java but unused. (In other words, free space in the Java heap.) |
TUPLEDATA | BIGINT | The amount of memory (in kilobytes) currently in use for storing database records. |
TUPLEALLOCATED | BIGINT | The amount of memory (in kilobytes) allocated for the storage of database records (including free space). |
INDEXMEMORY | BIGINT | The amount of memory (in kilobytes) currently in use for storing database indexes. |
STRINGMEMORY | BIGINT | The amount of memory (in kilobytes) currently in use for storing string, binary, and geospatial data that is not stored "in-line" in the database record. |
TUPLECOUNT | BIGINT | The total number of database records currently in memory. |
POOLEDMEMORY | BIGINT | The total size of memory (in kilobytes) allocated for tasks other than database records, indexes, and strings. (For example, pooled memory is used for temporary tables while processing stored procedures.) |
PHYSICALMEMORY | BIGINT | The total size of physical memory (in kilobytes) on the server. |
JAVAMAXHEAP | INTEGER | The maximum heap size (in kilobytes) of the Java runtime environment. |
PARTITIONCOUNT — Returns one row identifying the total number of partitions and the host that provided that information.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
PARTITION_COUNT | INTEGER | The number of unique or logical partitions on the cluster. When using a K value greater than zero, there are multiple copies of each logical partition. |
PLANNER — Returns a row for every planner cache. That is, one cache per execution site, plus one global cache per server. (The global cache is identified by a site and partition ID of minus one.)
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
SITE_ID | INTEGER | Numeric ID of the execution site on the host node. |
PARTITION_ID | INTEGER | The numeric ID for the logical partition that this site represents. When using a K value greater than zero, there are multiple copies of each logical partition. |
CACHE1_LEVEL | INTEGER | The number of query plans in the level 1 cache. |
CACHE2_LEVEL | INTEGER | The number of query plans in the level 2 cache. |
CACHE1_HITS | BIGINT | The number of queries that matched and reused a plan in the level 1 cache. |
CACHE2_HITS | BIGINT | The number of queries that matched and reused a plan in the level 2 cache. |
CACHE_MISSES | BIGINT | The number of queries that had no match in the cache and had to be planned from scratch |
PLAN_TIME_MIN | BIGINT | The minimum length of time (in nanoseconds) it took to complete the planning of ad hoc queries. |
PLAN_TIME_MAX | BIGINT | The maximum length of time (in nanoseconds) it took to complete the planning of ad hoc queries. |
PLAN_TIME_AVG | BIGINT | The average length of time (in nanoseconds) it took to complete the planning of ad hoc queries. |
FAILURES | BIGINT | The number of times planning for an ad hoc query failed. |
PROCEDURE — Returns a row for every stored procedure that has been executed on the cluster, grouped by execution site.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
SITE_ID | INTEGER | Numeric ID of the execution site on the host node. |
PARTITION_ID | INTEGER | The numeric ID for the logical partition that this site represents. When using a K value greater than zero, there are multiple copies of each logical partition. |
PROCEDURE | STRING | The class name of the stored procedure. |
INVOCATIONS | BIGINT | The total number of invocations of this procedure at this site. |
TIMED_INVOCATIONS | BIGINT | The number of invocations used to measure the minimum, maximum, and average execution time. |
MIN_EXECUTION_TIME | BIGINT | The minimum length of time (in nanoseconds) it took to execute the stored procedure. |
MAX_EXECUTION_TIME | BIGINT | The maximum length of time (in nanoseconds) it took to execute the stored procedure. |
AVG_EXECUTION_TIME | BIGINT | The average length of time (in nanoseconds) it took to execute the stored procedure. |
MIN_RESULT_SIZE | INTEGER | The minimum size (in bytes) of the results returned by the procedure. |
MAX_RESULT_SIZE | INTEGER | The maximum size (in bytes) of the results returned by the procedure. |
AVG_RESULT_SIZE | INTEGER | The average size (in bytes) of the results returned by the procedure. |
MIN_PARAMETER_SET_SIZE | INTEGER | The minimum size (in bytes) of the parameters passed as input to the procedure. |
MAX_PARAMETER_SET_SIZE | INTEGER | The maximum size (in bytes) of the parameters passed as input to the procedure. |
AVG_PARAMETER_SET_SIZE | INTEGER | The average size (in bytes) of the parameters passed as input to the procedure. |
ABORTS | BIGINT | The number of times the procedure was aborted. |
FAILURES | BIGINT | The number of times the procedure failed unexpectedly. (As opposed to user aborts or expected errors, such as constraint violations.) |
TRANSACTIONAL | TINYINT | 0 or 1. Reserved for future use. |
PROCEDUREDETAIL — Returns a row for every statement in every stored procedure that has been executed on the cluster, grouped by execution site.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
SITE_ID | INTEGER | Numeric ID of the execution site on the host node. |
PARTITION_ID | INTEGER | The numeric ID for the logical partition that this site represents. When using a K value greater than zero, there are multiple copies of each logical partition. |
PROCEDURE | STRING | The class name of the stored procedure. |
STATEMENT | STRING | The name of the statement in the stored procedure. Cumulative statistics for all statements in the procedure are included in a separate row labeled "<ALL>". |
INVOCATIONS | BIGINT | The total number of invocations of the statement at this site. |
TIMED_INVOCATIONS | BIGINT | The number of invocations used to measure the minimum, maximum, and average execution time. |
MIN_EXECUTION_TIME | BIGINT | The minimum length of time (in nanoseconds) it took to execute the statement. |
MAX_EXECUTION_TIME | BIGINT | The maximum length of time (in nanoseconds) it took to execute the statement. |
AVG_EXECUTION_TIME | BIGINT | The average length of time (in nanoseconds) it took to execute the statement. |
MIN_RESULT_SIZE | INTEGER | The minimum size (in bytes) of the results returned by the statement. |
MAX_RESULT_SIZE | INTEGER | The maximum size (in bytes) of the results returned by the statement. |
AVG_RESULT_SIZE | INTEGER | The average size (in bytes) of the results returned by the statement. |
MIN_PARAMETER_SET_SIZE | INTEGER | The minimum size (in bytes) of the parameters passed as input to the statement. |
MAX_PARAMETER_SET_SIZE | INTEGER | The maximum size (in bytes) of the parameters passed as input to the statement. |
AVG_PARAMETER_SET_SIZE | INTEGER | The average size (in bytes) of the parameters passed as input to the statement. |
ABORTS | BIGINT | In the cumulative row for each procedure ("<ALL>"), the number of times the procedure was aborted. For individual statements, this column is set to zero. |
FAILURES | BIGINT | The number of times the statement failed unexpectedly. (As opposed to user aborts or expected errors, such as constraint violations.) |
PROCEDUREINPUT — Returns a row for every stored procedure that has been executed on the cluster, summarized across the cluster.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
PROCEDURE | STRING | The class name of the stored procedure. |
WEIGHTED_PERC | BIGINT | A weighted average expressed as a percentage of the parameter set size for invocations of this stored procedure compared to all stored procedure invocations. |
INVOCATIONS | BIGINT | The total number of invocations of this procedure. |
MIN_PARAMETER_SET_SIZE | BIGINT | The minimum parameter set size in bytes. |
MAX_PARAMETER_SET_SIZE | BIGINT | The maximum parameter set size in bytes. |
AVG_PARAMETER_SET_SIZE | BIGINT | The average parameter set size in bytes. |
TOTAL_PARAMETER_SET_SIZE_MB | BIGINT | The total input for all invocations of this stored procedure measured in megabytes. |
PROCEDUREOUTPUT — Returns a row for every stored procedure that has been executed on the cluster, summarized across the cluster.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
PROCEDURE | STRING | The class name of the stored procedure. |
WEIGHTED_PERC | BIGINT | A weighted average expressed as a percentage of the result set size returned by invocations of this stored procedure compared to all stored procedure invocations. |
INVOCATIONS | BIGINT | The total number of invocations of this procedure. |
MIN_RESULT_SIZE | BIGINT | The minimum result set size in bytes. |
MAX_RESULT_SIZE | BIGINT | The maximum result set size in bytes. |
AVG_RESULT_SIZE | BIGINT | The average result set size in bytes. |
TOTAL_RESULT_SIZE_MB | BIGINT | The total output returned by all invocations of this stored procedure measured in megabytes. |
PROCEDUREPROFILE — Returns a row for every stored procedure that has been executed on the cluster, summarized across the cluster.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
PROCEDURE | STRING | The class name of the stored procedure. |
WEIGHTED_PERC | BIGINT | A weighted average expressed as a percentage of the execution time for this stored procedure compared to all stored procedure invocations. |
INVOCATIONS | BIGINT | The total number of invocations of this procedure. |
AVG | BIGINT | The average length of time (in nanoseconds) it took to execute the stored procedure. |
MIN | BIGINT | The minimum length of time (in nanoseconds) it took to execute the stored procedure. |
MAX | BIGINT | The maximum length of time (in nanoseconds) it took to execute the stored procedure. |
ABORTS | BIGINT | The number of times the procedure was aborted. |
FAILURES | BIGINT | The number of times the procedure failed unexpectedly. (As opposed to user aborts or expected errors, such as constraint violations.) |
QUEUE — Returns a separate row for each partition and host listing the current state of the process queue for that execution site.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
SITE_ID | INTEGER | Numeric ID of the execution site on the host node. |
CURRENT_DEPTH | INTEGER | The number of tasks currently in the queue. |
POLL_COUNT | BIGINT | The number of tasks that left the queue (and started executing) in the past five seconds. |
AVG_WAIT | BIGINT | The average length of time (in microseconds) tasks were waiting in the queue in the last five seconds. |
MAX_WAIT | BIGINT | The maximum length of time (in microseconds) tasks were waiting in the queue in the last five seconds. |
REBALANCE — Returns one row if the cluster is rebalancing. No data is returned if the cluster is not rebalancing.
Name | Datatype | Description |
---|---|---|
TOTAL_RANGES | BIGINT | The total number of partition segments to be migrated. |
PERCENTAGE_MOVED | FLOAT | The percentage of the total segments that have already been moved. |
MOVED_ROWS | BIGINT | The number of rows of data that have been moved. |
ROWS_PER_SECOND | FLOAT | The average number of rows moved per second. |
ESTIMATED_REMAINING | BIGINT | The estimated time remaining until the rebalance is complete, in milliseconds. |
MEGABYTES_PER_SECOND | FLOAT | The average volume of data moved per second, measured in megabytes. |
CALLS_PER_SECOND | FLOAT | The average number of rebalance work units, or transactions, executed per second. |
CALLS_LATENCY | FLOAT | The average execution time for rebalance transactions, in milliseconds. |
SNAPSHOTSTATUS — Returns a row for every snapshot file in the recent snapshots performed on the cluster.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
TABLE | STRING | The name of the database table whose data the file contains. |
PATH | STRING | The directory path where the snapshot file resides. |
FILENAME | STRING | The file name. |
NONCE | STRING | The unique identifier for the snapshot. |
TXNID | BIGINT | The transaction ID of the snapshot. |
START_TIME | BIGINT | The timestamp when the snapshot began (in milliseconds). |
END_TIME | BIGINT | The timestamp when the snapshot was completed (in milliseconds). |
SIZE | BIGINT | The total size, in bytes, of the file. |
DURATION | BIGINT | The length of time (in seconds) it took to complete the snapshot. |
THROUGHPUT | FLOAT | The average number of bytes per second written to the file during the snapshot process. |
RESULT | STRING | String value indicating whether the writing of the snapshot file was successful ("SUCCESS") or not ("FAILURE"). |
TYPE | STRING | String value indicating how the snapshot was initiated. Possible values are:
|
SNAPSHOTSUMMARY — Returns a row for every snapshot performed by the cluster, including up to ten snapshots
Name | Datatype | Description |
---|---|---|
NONCE | STRING | The unique identifier for the snapshot. |
TXNID | BIGINT | The transaction ID of the snapshot. |
TYPE | STRING | String value indicating how the snapshot was initiated. Possible values are:
|
PATH | STRING | The target directory path for the snapshot files. |
START_TIME | BIGINT | The timestamp when the snapshot began (in milliseconds). |
END_TIME | BIGINT | The timestamp when the snapshot was completed (in milliseconds). |
DURATION | BIGINT | The length of time (in seconds) it took to complete the snapshot. |
PROGRESS_PCT | FLOAT | For snapshots currently in progress, the percent complete at the time of the call. |
RESULT | STRING | String value indicating whether the writing of the snapshot was successful ("SUCCESS") or not ("FAILURE"). |
TABLE — Returns a row for every table, per partition. In other words, the number of tables, multiplied by the number of sites per host and the number of hosts.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | BIGINT | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
SITE_ID | BIGINT | Numeric ID of the execution site on the host node. |
PARTITION_ID | BIGINT | The numeric ID for the logical partition that this site represents. When using a K value greater than zero, there are multiple copies of each logical partition. |
TABLE_NAME | STRING | The name of the database table. |
TABLE_TYPE | STRING | The type of the table. Values returned include "PersistentTable" for normal data tables and views and "StreamedTable" for streams. |
TUPLE_COUNT | BIGINT | The number of rows currently stored for this table in the current partition. For streams, the cumulative total number of rows inserted into the stream. |
TUPLE_ALLOCATED_MEMORY | BIGINT | The total size of memory, in kilobytes, allocated for storing inline data associated with this table in this partition. The allocated memory can exceed the currently used memory (TUPLE_DATA_MEMORY). For streams, this field identifies the amount of memory currently in use to queue export data (both in memory and as export overflow) prior to its being passed to the export target. |
TUPLE_DATA_MEMORY | BIGINT | The total memory, in kilobytes, used for storing inline data associated with this table in this partition. The total memory used for storing data for this table is the combination of memory used for inline (tuple) and non-inline (string) data. |
STRING_DATA_MEMORY | BIGINT | The total memory, in kilobytes, used for storing non-inline variable length data (VARCHAR, VARBINARY, and GEOGRAPHY) associated with this table in this partition. The total memory used for storing data for this table is the combination of memory used for inline (tuple) and non-inline (string) data. |
TUPLE_LIMIT | INTEGER | The row limit for this table. Row limits are optional and are defined in the schema as a maximum number of rows that any partition can contain. If no row limit is set, this value is null. |
PERCENT_FULL | INTEGER | The percentage of the row limit currently in use by table rows in this partition. If no row limit is set, this value is zero. |
DR | STRING | A text string of "true" or "false" indicating whether the table is a DR table or not. |
EXPORT | STRING | If the table or stream is configured with MIGRATE or EXPORT TO TARGET, the name of the associated export target. |
TASK — Returns a row for every task, per logical partition.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | BIGINT | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
PARTITION_ID | BIGINT | The numeric ID for the logical partition running the task procedure. Directed procedures run on each logical partition. Multi-partition procedures run on the multi-partition initiator. |
TASK_NAME | STRING | The name of the task. |
STATE | STRING | The current status of the task. Possible values include:
|
SCOPE | STRING | The execution scope of the task, which matches the RUN ON attribute. Possible values are DATABASE, HOSTS, or PARTITIONS. |
SCHEDULER_INVOCATIONS | BIGINT | The total number of invocations of the task's schedule. For example, if the task is scheduled for every 5 minutes, after 20 minutes of normal operation you would expect 4 invocations. |
SCHEDULER_TOTAL_EXECUTION | BIGINT | The total time, in nanoseconds, consumed by the scheduler for scheduling the task. |
SCHEDULER_MIN_EXECUTION | BIGINT | The minimum amount of time, in nanoseconds, taken by the scheduler to schedule an instance of the task. |
SCHEDULER_MAX_EXECUTION | BIGINT | The maximum amount of time, in nanoseconds, taken by the scheduler to schedule an instance of the task. |
SCHEDULER_AVG_EXECUTION | BIGINT | The average amount of time, in nanoseconds, taken by the scheduler to schedule instances of the task. |
SCHEDULER_TOTAL_WAIT_TIME | BIGINT | The total time, in nanoseconds, between the task's scheduled start and when the scheduler was invoked. |
SCHEDULER_MIN_WAIT_TIME | BIGINT | The minimum difference, in nanoseconds, between when the task was scheduled to run and when the scheduler was invoked. |
SCHEDULER_MAX_WAIT_TIME | BIGINT | The maximum difference, in nanoseconds, between when the task was scheduled to run and when the scheduler was invoked. |
SCHEDULER_AVG_WAIT_TIME | BIGINT | The average difference, in nanoseconds, between when the task was scheduled to run and when the scheduler was invoked. |
SCHEDULER_STATUS | STRING | For future use. |
PROCEDURE_INVOCATIONS | BIGINT | The total number of invocations of the task's procedure. |
PROCEDURE_TOTAL_EXECUTION | BIGINT | The total time, in nanoseconds, consumed by the task for all of its invocations. |
PROCEDURE_MIN_EXECUTION | BIGINT | The minimum amount of time, in nanoseconds, an instance of the task took to execute. |
PROCEDURE_MAX_EXECUTION | BIGINT | The maximum amount of time, in nanoseconds, an instance of the task took to execute. |
PROCEDURE_AVG_EXECUTION | BIGINT | The average amount of time, in nanoseconds, instances of the task took to execute. |
PROCEDURE_TOTAL_WAIT_TIME | BIGINT | The total time, in nanoseconds, between when the procedure was scheduled to run and when it was invoked. |
PROCEDURE_MIN_WAIT_TIME | BIGINT | The minimum difference, in nanoseconds, between when the procedure was scheduled to run and when it was invoked. |
PROCEDURE_MAX_WAIT_TIME | BIGINT | The maximum difference, in nanoseconds, between when the procedure was scheduled to run and when it was invoked. |
PROCEDURE_AVG_WAIT_TIME | BIGINT | The average difference, in nanoseconds, between when the procedure was scheduled to run and when it was invoked. |
PROCEDURE_FAILURES | BIGINT | The number of times the procedure generated an error when run. |
TOPIC — Returns a separate row for each topic and partition.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
HOST_ID | INTEGER | Numeric ID for the host node. |
HOSTNAME | STRING | Server name of the host node. |
SITE_ID | INTEGER | Numeric ID of the execution site on the host node. |
TOPIC | STRING | The name of the topic. |
PARTITION_ID | INTEGER | The numeric ID for the logical partition. |
FIRST_OFFSET | BIGINT | The value of the first offset currently available in the topic. |
LAST_OFFSET | BIGINT | The value of the last offset in the topic. |
FIRST_OFFSET_TIMESTAMP | TIMESTAMP | The timestamp when the first offset was inserted into the queue. |
LAST_OFFSET_TIMESTAMP | TIMESTAMP | The timestamp when the most recent message (the last offset) was inserted into the queue. |
BYTES_ON_DISK | BIGINT | The size, in bytes, of data stored on disk for this partition and topic. |
BYTES_FETCHED | BIGINT | The size, in bytes, of data sent to consumers for this partition and topic. |
STATE | STRING | The current level of completeness for this topic in this partition. If the server was down at any point, it may be missing records that were queued while the partition was offline. Possible values are:
If a topic becomes blocked and the cluster is complete (has no missing nodes), you can use the voltadmin topic release command to "jump" past the missing offsets. |
MASTER | STRING | A text string of "true" or "false" indicating whether the current site is the master for the logical partition. |
RETENTION_POLICY | STRING | The retention policy for this topic. |
ROWS_SKIPPED | BIGINT | Reserved for future use. |
ERROR_OFFSET | BIGINT | If an error occurs while encoding a message for consumers, an error is returned to the consumer, the offset of the message is recoded here, and a description of the error stored in the next column. |
ERROR_MESSAGE | BIGINT | A description of the last error that occurred while encoding messages for consumers. |
TTL — Returns a separate row for each table in the database where TTL processing is currently active. It does not list tables that do not have TTL defined or where TTL processing has been cancelled due to an error or lack of a suitable index.
Name | Datatype | Description |
---|---|---|
TIMESTAMP | BIGINT | The timestamp when the information was collected (in milliseconds). |
TABLE_NAME | STRING | The name of the table. |
ROWS_DELETED | BIGINT | The total number of rows expired and deleted by the TTL attribute. |
ROWS_DELETED_LAST_ROUND | BIGINT | The number of rows expired and deleted during the last TTL processing. |
ROWS_REMAINING | BIGINT | The number of expired rows not deleted during the last TTL processing due to batch size limits. If TTL processing is keeping up with the throughput, this value should tend towards zero. |
LAST_DELETE_TIMESTAMP | BIGINT | The timestamp when the last round of TTL processing occurred (in milliseconds). |
The following example uses @Statistics to gather information about the distribution of table rows within the cluster:
$ sqlcmd 1> exec @Statistics TABLE, 0;
The next program example shows a procedure that collects and displays the number of transactions (i.e. stored procedures) during a given interval, by setting the delta flag to a non-zero value. By calling this procedure iteratively (for example, every five minutes), it is possible to identify fluctuations in the database workload over time (as measured by the number of transactions processed).
void measureWorkload() { VoltTable[] results = null; String procName; int procCount = 0; int sysprocCount = 0; try { results = client.callProcedure("@Statistics", "INITIATOR",1).getResults(); } catch (Exception e) { e.printStackTrace(); } for (VoltTable t: results) { for (int r=0;r<t.getRowCount();r++) { VoltTableRow row = t.fetchRow(r); procName = row.getString("PROCEDURE_NAME"); /* Count system procedures separately */ if (procName.substring(0,1).compareTo("@") == 0) { sysprocCount += row.getLong("INVOCATIONS"); } else { procCount += row.getLong("INVOCATIONS"); } } } System.out.printf("System procedures: %d\n" + "User-defined procedures: %d\n",+ sysprocCount,procCount); }