REST Client causes out of memory even if close is called.

[pzima]

REST Client causes out of memory even if close is called.

[plesingr-aeb]

I have investigated the issue in more detail and found the problem in the hk2-api library - see eclipse-ee4j/glassfish-hk2#949

[plesingr-aeb]

This causes us big problems in the production - our servers must be restarted frequently. Could somebody suggest us at least a workaround (manual cleanup)? I tried to analyze the heap dump but unfortunately i was not able to detect the original cause yet. It seems that ClientRuntime instances hang somewhere in
org.glassfish.hk2.internal.PerThreadContext$PerContextThreadWrapper.table(SystemDescriptor -> SecureSaxParserFactory).

[senivam]

As per the description, you would like to use one client for many requests. But in the reproducer you are creating as much clients as requests.

You can perfectly create one client for all requests like:

    @Test
    public void testMemoryConsumption() {
        int max = 100_000_000;
        try (final Client client = ClientBuilder.newClient()) {
            for (int i = 0; i < max; i++) {
                client.target(getBaseUri())
                        .path("memTest")
                        //.request(MediaType.APPLICATION_JSON)
                        .request(MediaType.APPLICATION_XML_TYPE)
                        .get(MemTestDto.class);
                if (i % 1_000 == 0) {
                    System.out.println("attempt=" + i);
                }
            }
        }
    }

and this will pass the test.

[plesingr-aeb]

Sure it will pass the test, but it does not solve the memory leak. We need to solve the leak.

At least, if we knew where the leak comes from (which package/class/method to look for it), we would definitely find a workaround. Could somebody, who knows the code a bit, help us, please?