Join us on May 14-15, 2019 at Forrester Digital Transformation & Innovation 2019 in Chicago, USA.
The default Joget installation comes with minimal performance configuration as it aims to cater for installation on small machines, e.g., a local development PC.
For production deployment on a server, the Java Virtual Machine (JVM), application server, database and operating systems should be tuned for performance. Actual real world performance depends on many factors. These include the deployment architecture, server and network specifications, complexity of the processes/apps, actual usage patterns by different users, etc.
This document presents some of the best practices in terms of performance tuning and optimization to get the best out of your deployment.
Important Note: These recommendations help to serve as general tips and guidelines, but in actual practice it would depend on each deployment’s unique environment. There are also many resources available online to help tune performance for Java, application servers and databases.
Installation as a Service
For production deployments, you may want to install the web application server, e.g., Apache Tomcat, as a service. Please refer to the documentation on the relevant operating system to do so. A guide to install Tomcat as a Windows service is available at Installing Joget as a Windows Service.
Java VM Configuration
Java VM Tuning
An important configuration would be the JVM memory allocation. If this is too low, the system will run out of memory. However if the setting is too high, there might be quite a large overhead in garbage collection. To get an optimum setting might require a bit of trial and error sometimes, depending on the usage environment.
Here are the steps to get started. You may want to start with a 1GB max heap setting and increase if the need arises.
1. Stop Joget.
2. Open and edit Joget Installation Directory/joget-start.bat.
4. Save and start Joget.
Please take note should you encounter any of the following OutOfMemory errors:
java.lang.OutOfMemoryError: Java heap space
Increase the maximum heap size -Xmx
java.lang.OutOfMemoryError: PermGen space
Increase the maximum permgen size -XX:MaxPermSize
java.lang.OutOfMemoryError: GC overhead limit exceeded
Enable the concurrent garbage collector -XX:+UseConcMarkSweepGC
For large or high load deployments, it is common to allocate at least 4GB or more, to as much as 75% of the physical RAM. Allocating too much might cause too much garbage collection overhead or physical memory swapping, so you will need to find a balance. There is an article at https://dzone.com/articles/5-tips-proper-java-heap-size that might help.
There are many online resources for further tuning, e.g., http://www.oracle.com/technetwork/java/performance-138178.html.
Web Application Server Configuration
Apache Tomcat Configuration
For Apache Tomcat, try setting the maxThreads Connector thread pool settings based on the estimated request load. For example, to set the maximum number of threads to 1000, edit tomcat_directory/conf/server.xml. Locate the line
and add a maxThreads="" such as
This would require a Tomcat restart to take effect.
In high load deployments on Apache Tomcat, you may encounter blocked threads on class loading too e.g. you will notice the following in thread dumps (https://blog.fastthread.io/2016/06/06/how-to-take-thread-dumps-7-options/.
This is actually a limitation in the default Apache Tomcat configuration, and can be fixed by using the ParallelWebappClassLoader loader https://bz.apache.org/bugzilla/show_bug.cgi?id=56530#c8
There are many other resources available online on Apache Tomcat performance tuning, e.g. http://www.itworld.com/networking/83035/tomcat-performance-tuning-tips.
Form data tables generated and managed by Joget are prefixed with app_fd. By default, primary keys and foreign keys are automatically generated for these tables where necessary.
However, in more complex apps, there would be more complex database queries that make use of these tables. As such, it is recommended for indexes to be added manually into table columns when required.
When using InnoDB in MySQL, setting an appropriate InnoDB Buffer Pool is important for large-scale performance. Details can be found here: https://dev.mysql.com/doc/refman/5.6/en/innodb-buffer-pool.html.
In environments with large data and queries, one way to improve performance is to use the query cache. This can help speed up query performance tremendously. Details can be found at https://dev.mysql.com/doc/refman/5.6/en/query-cache.html.
Note that from MySQL 5.6 onwards, the query cache has been disabled by default and needs to be manually configured as per the MySQL documentation.
You may need to increase the number of maximum connections allowed if there are a lot of concurrent requests. https://dev.mysql.com/doc/refman/5.0/en/too-many-connections.html
It is possible to identify slow queries in MySQL by enabling the slow query log. This helps to identify areas for possible indexing and optimization.
In high load deployments on MySQL, there are JDBC connection settings that can improve performance by reducing unnecessary round trip database calls when establishing transactions. These settings are useLocalSessionState and useLocalTransactionState (https://dev.mysql.com/doc/connector-j/5.1/en/connector-j-reference-configuration-properties.html). Be default, these settings are disabled as described in https://forums.mysql.com/read.php?39,626495,626512#msg-626512, but it can be enabled by setting the JDBC URL parameters in Custom Database Configuration e.g.
Linux OS Configuration
Linux / Unix systems have a limit on the number of files that can be concurrently opened by a process. When the limit is reached, there will be an exception "Too many open files". The default for most distributions is 1024, which will not be enough for high traffic deployments. In Linux, increasing the ulimit
works as a workaround but this is only valid for the session. For permanent configuration, please refer to documentation for the specific distribution, e.g., http://posidev.com/blog/2009/06/04/set-ulimit-parameters-on-ubuntu/.
Clustering and Load Balancing
For large scale and high-availability deployments, clustering and load balancing may need to be implemented using the Large Enterprise Edition.
A high-level description is as follows:
The main configuration is actually done at the web application server, in this case Apache Tomcat. There's a quite comprehensive documentation for this at http://tomcat.apache.org/tomcat-8.0-doc/cluster-howto.html.
You'll need a load balancer as well. This could be hardware or software, and it's possible to use Apache web server for this purpose. Using the mod_proxy_balancer module (http://httpd.apache.org/docs/2.2/mod/mod_proxy_balancer.html), traffic is directed to various Tomcat nodes. Depending on configuration, the approach could be load balanced or failover, and sticky sessions are recommended.
The database and wflow files (configuration/uploaded files) would also have to be shared from a centralized server.
More detailed information can be found at Joget Workflow Clustering Guide.
Logging and Troubleshooting
When running Apache Tomcat, logs are stored in the tomcat_directory/logs directory. In particular, the files joget.log, catalina.out, and localhost.yyyy-MM-dd.log capture information and errors that are generated.
Should you encounter any issues or errors, it is best that the following information is provided when reporting the issue to Enterprise Support or the community forums:
- Steps to reproduce the issue
- Copy of the log files mentioned above
- Screenshot(s) showing the problem
- Sample app that produces the issue
The more information provided, the faster an issue can be identified and resolved.
Backup and Restore
To backup an installation:
- Backup all configuration files and uploaded data files stored in joget_directory/wflow.
- Backup the database. e.g., in MySQL you can use the mysqldump utility.
To restore data to an installation:
- Restore all configuration files and uploaded data files stored in joget_directory/wflow.
- Restore the database.