It is important to understand that the BASE application can be spread on to several computers. The main BASE application is serving HTTP requests, the underlying database engine is providing storage and persistence of data, and job agents can be installed on computers that will serve the BASE installation with computing power and perform analysis and run plug-in. In a straight forward setup one computer provides all services needed for running BASE. From this starting point it is easy to add computers to shares load from the BASE server by installing job agents on these additional computers.
A job agent is a program running on a computer regularly checking the BASE job queue for jobs awaiting execution. When the job agent finds a job that it is enabled to execute, it loads the plug-in and executes it. Job agents will in this way free up resources on the BASE application server, and thus allow the BASE server to concentrate on serving web pages. Job agents are optional and must be installed and setup separately. However, BASE is prepared for job agent setup and to utilize the agents, but the agent are not required.
A job agent supports many configuration options that are not supported by the internal job queue. For example, you can
Specify exactly which plug-ins each job agent should be able to execute.
Give some plug-ins higher priority than other plug-ins.
Specify which users/groups/projects should be able to use a specific job agent.
Override memory settings and more for each plug-in.
Execute plug-ins in separate processes. Thus, a misbehaving plug-in cannot bring the main application server down.
Add more computers with job agents as needed.
All these options make it possible to create a very flexible setup. For example one job agent can be assigned for importing data only, another job agent can be assigned for running analysis plug-ins for specific project only, and a third may be a catch-all job agent that performs all low-priority jobs.
should be set to
false for the
BASE server. This setting is found in
file. The changes will not take effect until the
application server is restarted.
|Prior to BASE 2.5 the internal job queue had to be disabled completely. This is no longer the case since it is possible to enable/disable the internal job queue separately for each plug-in.|
During installation of BASE a user account is created
for the job agent. This account is used by the job
agents to log on to BASE. The account is disabled by
default and must be enabled. Enable the account and
set a password using the BASE web interface.
The same password must also be set in the
jobagent.properties file, see
This is the similar to granting database access for the BASE server user in the in the regular BASE installation, cf. BASE (database engine). You must create an account in the database that is allowed to connect from the job agent server. MySQL example:
GRANT ALL ON base2.* TO firstname.lastname@example.org IDENTIFIED BY 'db_password'; GRANT ALL ON base2dynamic.* TO email@example.com;
job.agent.host with the
host name of the server that is going to run the job
agent. You should also set password. This password is
used in item
below in job agent server setup. You can use the same
database user and password as in the regular database
You must use the same version on the web server and all job agents. You find the downloads at http://base.thep.lu.se/wiki/DownloadPage
file must be configured as in regular BASE
to use the same database as the web server
application. The most important settings are
db.username: The database
user you created in item
Create a user account on the database
db.password: The password for
db.url: The connection url to
userfiles: The path to the
directory where user files are located. This
directory must be accessible from all job
agents, i.e., by nfs or other file system
See the Appendix C, base.config reference for
more information about the settings in
file contains settings for the job agent. The most
important ones to specify value for are
agent.password: The password
you set for the job agent user account in item
Enable the job agent user account
agent.id: An ID that must be
unique for each job agent accessing the BASE application.
name/ip address of the web server if you want it
to be able to display info about running
jobs. The job agent will only allow connections
from computers specified in this setting.
contains many more configuration options. See
the Appendix G, jobagent.properties reference for
bin directory, register
the job agent with
bin directory, start the
job agent with
./jobagent.sh start &
See the Appendix H, jobagent.sh reference for more information about what you can do with the job agent command line interface.
Before the job agent starts executing jobs for you it must be configured. The configuration is done through the BASE web interface. See Section 22.3, “Job agents”
Go to the→ → menu.
Select the job agent and click on thebutton.
On the Plugins tab you can specify which plug-ins the job agent should handle. Note that if you have installed external plug-ins on the web server, those plug-ins must be installed on the job agent as well. It is possible to specify different paths to the JAR file for each job agent.
Use the regular Share
functionality to specify which users/groups/projects
should be able to use the job agent. You must give
them at least