Following up on the Performance tuning in Liferay – Part 1 post – here are some additional points for performance tuning:

1. The blue circle in Glowroot slow traces indicates that the transaction is still ongoing whereas yellow indicates it’s completed. Red indicates there is an error.
2. You can change the JVM gauges as needed to see lot of different types of details of JVM
3. You can use instrumentation from configuration using type ahead drop down (AJAX style)
4. You can allocate specific cores to a JVM if need be using an argument on core allotment
5. You can see thread profiles and take heap dumps from Glowroot itself
6. Glowroot has sections on errors, queries and service calls
7. You can get Glowroot to sustain it’s data through restarts using arguments
8. For frequent garbage collection, check if some queries, etc. are continuously filling up memory and any fine tuning on caching can help
9. It helps to follow these sections in no particular order and check them regularly: JVM – guages, MBeans (You can search your cache related things here – it’s like seeing things in VisualVM), threads and more, transactions, slow traces (all three areas throughput/etc.), thread profiles (search “blocked” here), queries, service calls, errors, sorting options in transactions, instrumentation, etc.
10. Latest Glowroot works with Java 11 that is compatible with Liferay for customizations and product usage but not source code compile. This latest Glowroot gives lot many more options especially in transactions.
11. If you are using Java 8, check if your Glowroot version is compatible with it. Typically 0.13.6 and below are compatible with Java 8 as far as I know.

Email me: Neil@HarwaniSystems.in