@SystemInformation

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@SystemInformation

@SystemInformation — Returns configuration information about VoltDB and the individual nodes of the database cluster.

Synopsis

@SystemInformation

@SystemInformation String component

Description

The @SystemInformation system procedure returns information about the configuration of the VoltDB database or the individual nodes of the database cluster, depending upon the component keyword you specify. The following are the allowable values of component:

"DEPLOYMENT": Returns information about the configuration of the database. In particular, this keyword returns information about the various features and settings enabled through the configuration file, such as export, snapshots, K-safety, and so on. These properties are returned in a single VoltTable of name/value pairs.
"LICENSE": Returns information about the license in use by the database. The license properties are returned in a single VoltTable of name/value pairs.
"OVERVIEW": Returns information about the individual servers in the database cluster, including the host name, the IP address, the version of VoltDB running on the server, as well as the path to the configuration file in use. The overview also includes entries for the start time of the server and length of time the server has been running.

If you do not specify a component, @SystemInformation returns the results of the OVERVIEW component (to provide compatibility with previous versions of the procedure).

Return Values

Returns one of two VoltTables depending upon which component is requested.

DEPLOYMENT — returns one row for each configuration property.

Name	Datatype	Description
PROPERTY	STRING	The name of the configuration property. The system procedure reports the following properties, depending on what features are enabled in the database configuration: adminport — admin port number commandlogenabled — whether command logging is enabled or not commandlogfreqtime — frequency of command logging in milliseconds commandlogfreqtxns — frequency of command logging in number of transactions commandlogmode — command logging mode, sync or async commandlogpath — directory path to command log segments commandlogsnapshotpath — directory path to command log snapshots elasticduration — target duration of rebalance transactions in milliseconds elasticthroughput — target throughput of rebalance transactions in MB/second export — whether export is enabled or not exportoverflowpath — directory path to export overflow heartbeattimeout — heartbeat timeout setting in seconds hostcount — full number of servers in the cluster httpenabled — whether the httpd port is enabled or not httpport — httpd port number jsonenabled — whether JSON is enabled on the httpd port or not kfactor — K-safety value partitiondetection — whether network partition detection is enabled or not querytimeout — default query timeout in seconds sitesperhost — number of sites per host snapshotenabled — whether automatic snapshots are enabled or not snapshotfrequency — frequency of automatic snapshots snapshotpath — directory path to automatic snapshot files snapshotprefix — unique file prefix for automatic snapshots snapshotpriority — system priority of automatic snapshots snapshotretain — number of automatic snapshots to retain temptablesmaxsize — maximum size of the temp tables users — list of user names and their roles voltdbroot — path of database root directory
VALUE	STRING	The corresponding value of that property in the configuration file (either explicitly or by default).

LICENSE — returns one row for each license property.

Name	Datatype	Description
PROPERTY	STRING	The name of the license property. The system procedure reports the following properties, depending on what license features are enabled: PERMIT_VERSION — for internal use PERMIT_SCHEME — for internal use TYPE — the type of license in use ISSUER_COMPANY — the company that issued the license ISSUER_EMAIL — the email address of the company that issued the license ISSUER_URL — the website of the company that issued the license ISSUER_PHONE — the telephone number of the company that issued the license ISSUE_DATE — the date the license was issued LICENSEE — who the license was issued to EXPIRATION — the date the license expires HOSTCOUNT_MAX — the maximum number of hosts supported by the license FEATURES_TRIAL — whether this is a trial license or not FEATURES_UNRESTRICTED — whether the license allows unrestricted access to all features FEATURES_COMMANDLOGGING — whether the license supports the use of command logging FEATURES_DRREPLICATION — whether the license supports the use of passive database replication (DR) FEATURES_DRACTIVEACTIVE — whether the license supports the use of cross data center replication (XDCR) NOTE — notes regarding the license SIGNATURE — an encrypted signature identifying the license (for internal use)
VALUE	STRING	The corresponding value of the property (either set explicitly by the license or by default).

OVERVIEW — returns a row for every system attribute one every node of the cluster. The rows contain an additional column to identify the host node associated with the attribute.

Name	Datatype	Description
HOST_ID	INTEGER	A numeric identifier for the host node.
KEY	STRING	The name of the system attribute.
VALUE	STRING	The corresponding value of that attribute for the specified host. The system procedure reports the following properties: ADMININTERFACE — admin network interface ADMINPORT — admin port number BUILDSTRING — VoltDB software build string including version number CATALOG — for internal use CATALOGCRC — for internal use CLIENTINTERFACE — client network interface CLUSTERID — DR cluster ID CLUSTERSAFETY — whether the database is running in normal K-safe mode (FULL), or if it has reduced k-safety due to non-deterministic results from a transaction (REDUCED) CLUSTERSTATE — whether the database is running normally or paused (that is, in admin mode) DEPLOYMENT — path to current configuration in root directory DRINTERFACE — database replication (DR) network interface DRPORT — database replication (DR) port number DRPUBLICINTERFACE — network interface advertised to member clusters as DR interface DRPUBLICPORT — port advertised to member clusters as DR port FULLCLUSTERSIZE — initial cluster size HOSTNAME — server host name HTTPINTERFACE — httpd network interface HTTPPORT — httpd port number INITIALIZED — for internal use INTERNALINTERFACE — internal network interface INTERNALPORT — internal port number IPADDRESS — server IP address IV2ENABLED — for internal use LAST_UPDATECORE_DURATION — length of last schema change transaction LICENSE — product license information LOG4JPORT — log4J port number PARTITIONGROUP — for internal use PLACEMENTGROUP — name of the placement group the server belongs to PUBLICINTERFACE — network interface advertised by VoltDB Management Center as the external interface REPLICATIONROLE — database replication (DR) role, MASTER, REPLICA, XDCR, or none STARTTIME — timestamp when cluster started UPTIME — how long the cluster has been running VERSION — VoltDB software version number VOLTDBROOT — path of database root directory ZKINTERFACE — ZooKeeper network interface ZKPORT — ZooKeeper port number

Examples

The first example displays information about the individual servers in the database cluster:

$ sqlcmd
1> exec @SystemInformation overview;

The following program example uses @SystemInformation to display information about the nodes in the cluster and then about the database itself.

VoltTable[] results = null;
try {
     results = client.callProcedure("@SystemInformation",
               "OVERVIEW").getResults();
     System.out.println("Information about the database cluster:");
     for (VoltTable node : results) System.out.println(node.toString());

     results = client.callProcedure("@SystemInformation",
               "DEPLOYMENT").getResults();
     System.out.println("Information about the database configuration:");
     for (VoltTable node : results) System.out.println(node.toString());

}
catch (Exception e) {
     e.printStackTrace();
}

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