How did you determine that the system was overwhelmed, what errors occurred, and why was there an Out of Memory?

The determination that a system is not coping usually begins with monitoring performance and logs. Common Out of Memory (OOM) errors occur when the JVM lacks sufficient available memory to allocate new objects.

Causes of OOM can include:

• Memory leaks — objects are not released due to improper reference management.
• Incorrect heap size configuration — too little memory is allocated.
• Unexpectedly large data volume in processing.

For diagnostics, profiling tools (such as VisualVM, YourKit) are used to analyze heap dumps to find objects that occupy a lot of memory. JVM settings are also checked, and code is optimized to reduce memory consumption.