From the TimeMachine Scheduler download page you will see that the latest 1.2.1 release zip package size is around 13M. It may seem large for a scheduler application, but let's examine it closely to see what's in there. Here is how the zip package looks like inside
timemachine-scheduler-1.2.1 +-- bin +-- lib +-- config
The config directory contains many sample configurations and scripts to help new users get started. The bin contains few startup wrapper scripts that let you start the scheduler. The lib contains the libraries for the scheduler application. I want to go into more details on these.
+-- lib -rw-r--r--@ 1 zemian staff 445288 Jun 20 23:20 antlr-2.7.7.jar -rw-r--r--@ 1 zemian staff 610790 Jun 20 23:26 c3p0-0.9.1.2.jar -rw-r--r--@ 1 zemian staff 109043 Jun 20 23:20 commons-io-1.4.jar -rw-r--r--@ 1 zemian staff 279193 Jun 20 23:20 commons-lang-2.5.jar -rw-r--r--@ 1 zemian staff 313898 Jun 20 23:26 dom4j-1.6.1.jar -rw-r--r--@ 1 zemian staff 6156866 Aug 2 22:05 groovy-all-2.0.0.jar -rw-r--r--@ 1 zemian staff 1267149 Jun 20 23:26 h2-1.3.163.jar -rw-r--r--@ 1 zemian staff 81271 Jun 20 23:26 hibernate-commons-annotations-4.0.1.Final.jar -rw-r--r--@ 1 zemian staff 4407494 Jun 20 23:26 hibernate-core-4.1.3.Final.jar -rw-r--r--@ 1 zemian staff 102661 Jun 20 23:26 hibernate-jpa-2.0-api-1.0.1.Final.jar -rw-r--r--@ 1 zemian staff 648253 Jun 20 23:26 javassist-3.15.0-GA.jar -rw-r--r--@ 1 zemian staff 60768 Jun 20 23:26 jboss-logging-3.1.0.GA.jar -rw-r--r--@ 1 zemian staff 11209 Jun 20 23:26 jboss-transaction-api_1.1_spec-1.0.0.Final.jar -rw-r--r--@ 1 zemian staff 481535 Jun 20 23:20 log4j-1.2.16.jar -rw-r--r--@ 1 zemian staff 25496 Jun 20 23:20 slf4j-api-1.6.1.jar -rw-r--r--@ 1 zemian staff 9753 Jun 20 23:20 slf4j-log4j12-1.6.1.jar -rw-r--r--@ 1 zemian staff 46885 Aug 2 22:37 timemachine-hibernate-1.2.1.jar -rw-r--r--@ 1 zemian staff 154925 Aug 2 22:36 timemachine-scheduler-1.2.1.jar
The core of the scheduler timemachine-scheduler-1.2.1.jar would only need slf4j-api-1.6.1.jar, commons-io-1.4.jar and commons-lang-2.5.jar to run. These would support full scheduler with in memory data store. As you can see these add up to only about 500K!
To be able to see useful logging output, you need an SLF4j impl. You may use built-in JDK's logger if you choose, or you may use slf4j-log4j12-1.6.1.jar and log4j-1.2.16.jar. I personally think the JDK logger is horrible to use and configure, so I package up log4j as option for you.
The TimeMachine allows you to switch data store service. We provided the HibernateDataService service in timemachine-scheduler-1.2.1.jar. This service would require the Hibernate dependencies, which is pretty heavy. They are: hibernate-*.jar, jboss-*.jar, javassist-3.15.0-GA.jar, antlr-2.7.7.jar, and dom4j-1.6.1.jar. These can add up to another 5M in size!
Now with the Hibernate data service, you would also need a database driver that match to your database. I have included a H2Database, a Java database that provides full SQL database service including its driver in h2-1.3.163.jar. This alone is about 1.2M in size.
When you working with Hibernate and Database, you should always use a Database connection pool. I packaged the c3p0-0.9.1.2.jar implementation which Hibernate can automatically detects.
I hope these information can help you decide what to remove or add in case you want to customize your scheduler to fit into your application. You may also visit the project to see the Maven site dependencies report that has all the details. This also means that if you use Maven to bring in TimeMachine scheduler as dependency, you will automatically gets the minimal because I have carefully set all the optional items not to be included with the proper Maven scopes.