Basic Scheduler

Table of contents 

Description

The Scheduler (Quartz) Component is introduced to be able to facilitate multi-node environments. This is used for evaluation cases and task in a DCM project (or a project that uses the process engine). Please consider if the advanced scheduler is more suitable for your situation. In the Basic scheduler the evaluation of task is done by a polling mechanism. Every time the interval expires the process engine starts evaluation for a project.

More information about the basic scheduler can be found at the Process Engine page.

Requirements

This component is configured to persist data in memory by default for demo and standalone development purpose, but we strongly advice to persist data in a database. See platform support for the supported databases.

Installation

Steps:

1. Add scheduler-quartz to the list of spring active profiles in the bootstrap.properties (this profile is active when using the installer). More information on how to configure the application using Spring Profiles can be found here: External application configuration with Spring Profiles.
2. Add the application-scheduler-quartz.properties file in the configuration location. This properties file is added in the 
   spring.config.additional-location
   when using the installer. Otherwise, please create this according to the documentation below.
3. Run the provided scripts for creating the quartz tables in the database: msssql.sql or oracle.sql. The scripts are located in the release zip in \Runtime\Java\Webapp\DBScripts\blueriq-component-scheduler-quartz
4. Define quartz database connection in the application-externaldatasources.properties file.

Configuration

In order to tune resources for job execution we provided a few details about the Thread Pool.

Quartz is configured using a set of properties. Quartz uses a job store in order to persist jobs details, triggers and other job related information. We support two types of job stores:

• Memory (default) ^{for demo's and standalone development}
  
• Database ^recommended
  

Memory (default)

By default memory mode is enabled which should not be used unless for demo's and standalone development. For recommended settings please check the database settings. For memory the following setting should appear in the quartz.properties.

spring.quartz.job-store-type=memory

Database

Scripts to create the required database content are provided for the following databases:

• SQL Server
• Oracle

There are two types of connection that are supported:

1. JDBC Connection
2. JNDI Connection

JDBC Connection

To enable the JDBC Connection the externaldatasources profile must enabled and the following properties have to be used:

spring.quartz.job-store-type=jdbc
spring.quartz.properties.org.quartz.jobStore.tablePrefix=QRTZ_

blueriq.datasource.scheduler-quartz.driverClassName=com.microsoft.sqlserver.jdbc.SQLServerDriver
blueriq.dataSource.scheduler-quartz.url=jdbc:sqlserver://<server_url>:<port>;databaseName=<database_name>;instance=SQL_EXPRESS
blueriq.datasource.scheduler-quartz.username=<user>
blueriq.datasource.scheduler-quartz.password=<password>

blueriq.datasource.scheduler-quartz.driverClassName=oracle.jdbc.driver.OracleDriver
blueriq.dataSource.scheduler-quartz.url=jdbc:oracle:thin:@<server_url>:<port>:xe
blueriq.datasource.scheduler-quartz.username=<user>
blueriq.datasource.scheduler-quartz.password=<password>

JobStoreTX allows Quartz managing quartz related transactions. 

JDBCJobStore’s “table prefix” property is a string equal to the prefix given to Quartz’s tables that were created in your database. You can have multiple sets of Quartz’s tables within the same database if they use different table prefixes.

JNDI Connection

To enable JNDI Connection jndidatasources profile must be activated and the following properties have to be used:

spring.quartz.properties.org.quartz.jobStore.class=org.quartz.impl.jdbcjobstore.JobStoreCMT
spring.quartz.properties.org.quartz.jobStore.tablePrefix=QRTZ_

// JBoss Example provided that the jndi name is set to java:jboss/jdbc/quartzdb
blueriq.datasource.scheduler-quartz.jndiName=java:jboss/jdbc/quartzdb

// Tomcat Example provided that the jndi name is set to jdbc/quartzdb
blueriq.datasource.scheduler-quartz.jndiName=java:/comp/env/jdbc/quartzdb

JobStoreCMT relies upon transactions being managed by the application which is using Quartz. 

Thread Pool

If the Database configuration is chosen we recommend to also add the thread pool with the following default values:

The quartz documentation suggests the following configuration: provided that the database allows X connections, then the threadCount must be set to X - 3.

If a JNDI connection is used, then the connection that is behind the JNDI name defines a max number of connections in the pool - say Y. In this case the thread count must be Y - 3.

Thread Pool properties are the following:

spring.quartz.properties.org.quartz.threadPool.class=org.quartz.simpl.SimpleThreadPool
spring.quartz.properties.org.quartz.threadPool.threadCount=2