Heap Memory Overflow - Internship Memo

Apr 13, 202350

AI Translation

This post is translated from Chinese into English through AI.View Original

AI-generated summary

The research platform encountered an error in the production environment, showing "oom-Java heap space". After checking for large objects or recursive code, the memory was expanded. Opening any PDF failed, possibly due to memory not being released. The program's memory usage was consistently increasing, and it was found that the issue was continuous creation of font objects. The solution was to make the creation of font objects a static variable instead of creating them in a static function. This was the first time experiencing a heap memory overflow in production.

Background: Research platform for internal information and literature queries.
Formal environment error, displaying oom-Java heap space. First, check if there are any large objects or recursive code created, then appropriately increase the memory. Opening any PDF fails, possibly due to memory not being released (suspecting a bug in the PDF reading tool). Used jconsole to observe the memory changes during program execution, and the memory consistently increased. Local analysis showed continuous object creation. Analyzed heap memory snapshot (XX:+HeapDumpOnOutOfMemoryError heap memory snapshot can be added later), preliminary analysis showed continuous invocation of the interface for generating font objects, which means continuous creation of font objects.
Once the source is found, it's easy to handle. Found the code that continuously creates objects for this interface, should extract it as a static variable instead of creating it in the static function every time.

PS: Encountering heap memory overflow for the first time in production was quite exciting. (Just that the formatting of the editing was terrible, need to practice in this area.)