GCViewer | Tagtraum stopped development | Code Editor library

Without knowledge of your application, here are some general thoughts:

• Your application seems to have a high amount of long-lived objects (only 9gb of the tenured generation get collected, 15gb remain), which cause your problems: While allocation speed determines the frequency of GC pauses it is the amount of living objects (that cannot be freed by GC) which determines the length of the GC pauses.
• One possible cause could be that your application acts as an in-memory database to some extent. That is, the objects are not needed all the time, but are not written to a database to retain fast in-memory access to them. In that case, you should store them off-heap (in memory not managed by the GC) or use an in-memory database, e.g. Redis. This way, they will be accessible with low latency but won't be considered by the GC because they won't be reclaimed anyway.
• Another possible solution might be to tune your GC settings: You could switch to G1, increase the size of your young generation or increase the promotion threshold; or a combination of those. Increasing the young generation and reducing promotion might lead to much less growth of the tenured generation and thus to less frequent major collections. Switching to the G1 collector would give you the benefit that this collector is able to only consider some survivor regions and can leave regions with immortal objects alone.