Java

In a fleet of dozens of services it is hard to tell which of them already use faster startup with AppCDS or the AOT cache, which garbage collector each of them runs, and where GC logging is on. The Java dashboard answers this for the whole fleet at once.

The page is read-only and available to every authenticated user: VIEWER, EDITOR, ADMIN, and SUPER_ADMIN can all open it. See Roles and authorities for the full role/authority matrix.

What the page shows

For each JVM feature, the page shows the share of services that use it:

• Project Leyden: services that start with AppCDS (-XX:SharedArchiveFile) or with the AOT cache (-XX:AOTCache), each separately and both together.
• Garbage collectors: which garbage collector what share of services runs, for example G1, Parallel, or ZGC. The most common one is highlighted separately.
• GC logging: services where GC logging is on right now, including services where it was turned on from Axelix. See Enabling GC logging.
• Project Lilliput: services with compact object headers (-XX:+UseCompactObjectHeaders).

How it works

The dashboard counts what each service reports about its JVM. Master records it once a day and uses the latest record. A service counts once however many instances it runs.

See also

• Garbage Collector
• Languages Profile
• Persistence