Memory Leak Scenario
Memory leaks are likely to occur when a long-lived object holds a reference to a short-lived object. Although the short-lived object is no longer needed, because Holding its reference for a long life cycle prevents it from being recycled. This is the scenario where memory leaks occur in Java.
1. Check the CPU and memory usage during the process:
top –H –p 58527
2. Check the server memory.
df -h 查看磁盘情况 du -h --max-depth=1 文件目录占用资源情况。
3. Check the memory, cache area, usage and idleness.
free -m
S0C: The capacity (bytes) of the first survivor (survivor area) in the young generation
S1C: The second survivor in the young generation (bytes) The capacity of the survivor area (bytes)
S0U: The first survivor (survivor area) in the young generation currently uses space (bytes)
S1U: The second survivor in the young generation The survivor (survival area) currently uses space (bytes)
EC: The capacity of Eden (Eden) in the young generation (bytes)
EU: The current capacity of Eden (Eden) in the young generation Used space (bytes)
OC: Old generation capacity (bytes)
OU: Old generation currently used space (bytes)
PC: Perm (Persistent Generation) capacity (bytes)
PU: Perm (persistent generation) currently used space (bytes)
YGC: gc in the young generation from application startup to sampling Times
YGCT: Time (s) used for gc in the young generation from application startup to sampling time
FGC: Number of gcs from application startup to old generation (full gc) during sampling
FGCT: The time (s) used for gc from the application startup to the old generation (full gc) during sampling
GCT: The total time (s) used for gc from application startup to sampling time
4. View the execution program information.
jstack 2829 > 1.log grep -A 1'java.lang.Thread.State' jstack.log | wc -l
5. Download the heap file analysis code Dump.
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