Clustered Session Management: JDBC

Clustered Session Management: JDBC
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Enabling JDBC Sessions
Configuring JDBC Session Properties

Enabling JDBC Sessions

When using the Jetty distribution, you will first need to enable the session-store-jdbc module for your Jetty base using the --add-to-start argument on the command line.

$ java -jar ../start.jar --create-startd
INFO : Base directory was modified

$ java -jar ../start.jar --add-to-start=session-store-jdbc
INFO  : server          transitively enabled, ini template available with --add-to-start=server
INFO  : sessions        transitively enabled, ini template available with --add-to-start=sessions
INFO  : sessions/jdbc/datasource dynamic dependency of session-store-jdbc
INFO  : session-store-jdbc initialized in ${jetty.base}/start.d/session-store-jdbc.ini
INFO  : Base directory was modified

Doing this enables the JDBC Session module and any dependent modules or files needed for it to run on the server. The example above is using a fresh ${jetty.base} with nothing else enabled.

When the --add-to-start argument was added to the command line, it enabled the the session-store-jdbc module as well as the sessions and server modules, which are required for JDBC session management to operate.

In addition to adding these modules to the classpath of the server, several ini configuration files were added to the ${jetty.base}/start.d directory.

Configuring JDBC Session Properties

Opening the start.d/session-store-jdbc.ini will show a list of all the configurable options for the JDBC module:

# ---------------------------------------
# Module: session-store-jdbc
# Enables JDBC peristent/distributed session storage.
# ---------------------------------------
--module=session-store-jdbc

##
##JDBC Session properties
##

#jetty.session.gracePeriod.seconds=3600

## Connection type:Datasource
db-connection-type=datasource
#jetty.session.jdbc.datasourceName=/jdbc/sessions

## Connection type:driver
#db-connection-type=driver
#jetty.session.jdbc.driverClass=
#jetty.session.jdbc.driverUrl=

## Session table schema
#jetty.session.jdbc.schema.accessTimeColumn=accessTime
#jetty.session.jdbc.schema.contextPathColumn=contextPath
#jetty.session.jdbc.schema.cookieTimeColumn=cookieTime
#jetty.session.jdbc.schema.createTimeColumn=createTime
#jetty.session.jdbc.schema.expiryTimeColumn=expiryTime
#jetty.session.jdbc.schema.lastAccessTimeColumn=lastAccessTime
#jetty.session.jdbc.schema.lastSavedTimeColumn=lastSavedTime
#jetty.session.jdbc.schema.idColumn=sessionId
#jetty.session.jdbc.schema.lastNodeColumn=lastNode
#jetty.session.jdbc.schema.virtualHostColumn=virtualHost
#jetty.session.jdbc.schema.maxIntervalColumn=maxInterval
#jetty.session.jdbc.schema.mapColumn=map
#jetty.session.jdbc.schema.table=JettySessions

jetty.session.gracePeriod.seconds: Amount of time, in seconds, to wait for other nodes to be checked to verify an expired session is in fact expired throughout the cluster before closing it.
jetty.session.savePeriod.seconds=0: By default whenever the last concurrent request leaves a session, that session is always persisted via the SessionDataStore, even if the only thing that changed on the session is its updated last access time. A non-zero value means that the SessionDataStore will skip persisting the session if only the access time changed, and it has been less than savePeriod seconds since the last time the session was written.
Note
Configuring savePeriod is useful if your persistence technology is very slow/costly for writes. In a clustered environment, there is a risk of the last access time of the session being out-of-date in the shared store for up to savePeriod seconds. This allows the possibility that a node may prematurely expire the session, even though it is in use by another node. Thorough consideration of the maxIdleTime of the session when setting the savePeriod is imperative - there is no point in setting a savePeriod that is larger than the maxIdleTime.
db-connection-type: Set to either datasource or driver depending on the type of connection being used.
jetty.session.jdbc.datasourceName: Name of the remote datasource.
jetty.session.jdbc.driverClass: Name of the JDBC driver that controls access to the remote database, such as com.mysql.jdbc.Driver
jetty.session.jdbc.driverUrl: Url of the database which includes the driver type, host name and port, service name and any specific attributes unique to the database, such as a username. As an example, here is a mysql connection with the username appended: jdbc:mysql://127.0.0.1:3306/sessions?user=sessionsadmin.

The jetty.sessionTableSchema values represent the names for the columns in the JDBC database and can be changed to suit your environment.

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