the memory in the old generation isn't GC in time, with code sessionPool.showPathsTemplateSetOn
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- Java
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Description
When run the code below, the memory in the old generation isn't GC in time, which eventually leads to the data node crashing.
Version
version: 1.3.2
### log :
A fatal error has been detected by the Java Runtime Environment:
Internal Error (debug.cpp:362), pid=32562, tid=88579
fatal error: OutOfMemory encountered: Java heap space
JRE version: OpenJDK Runtime Environment Corretto-17.0.11.9.1 (17.0.11+9) (build 17.0.11+9-LTS)
Java VM: OpenJDK 64-Bit Server VM Corretto-17.0.11.9.1 (17.0.11+9-LTS, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, bsd-aarch64)
--------------- S U M M A R Y ------------
Command Line: --add-opens=java.base/java.util.concurrent=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.nio=ALL-UNNAMED --add-opens=java.base/java.io=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED -Dlogback.configurationFile=./sbin/../conf/logback-datanode.xml -DIOTDB_HOME=./sbin/.. -DIOTDB_DATA_HOME=./sbin/.. -DTSFILE_HOME=./sbin/.. -DIOTDB_CONF=./sbin/../conf -DTSFILE_CONF=./sbin/../conf -Dname=iotdb\.IoTDB -DIOTDB_LOG_DIR=./sbin/../logs -DOFF_HEAP_MEMORY=1232M -Diotdb.jmx.local=true -Xms4912M -Xmx4912M -XX:MaxDirectMemorySize=1232M -Djdk.nio.maxCachedBufferSize=1291845 -XX:+CrashOnOutOfMemoryError -XX:+UseAdaptiveSizePolicy -Xss512k -XX:SafepointTimeoutDelay=1000 -XX:+SafepointTimeout org.apache.iotdb.db.service.DataNode -s
Host: "Mac14,7" arm64, 8 cores, 16G, Darwin 23.4.0, macOS 14.4 (23E214)
Time: Thu Dec 12 22:29:33 2024 CST elapsed time: 33.258095 seconds (0d 0h 0m 33s)
### code:
```
public class SessionPoolDemo {
private static SessionPool sessionPool;
private static void constructCustomSessionPool() {
sessionPool = new SessionPool.Builder()
.host("127.0.0.1")
.port(6667)
.user("root")
.password("root")
.build();
}
public static void main(String[] args) throws Exception {
constructCustomSessionPool();
for (int i = 0; i < 1000; i++) { // or 5000
List locationTemplate = sessionPool.showPathsTemplateSetOn("locationTemplate");
System.out.println(locationTemplate.size());
}
}
}
```
### GC:
Contributor guide
Research direction
Start with the SessionPool.showPathsTemplateSetOn call used in the SessionPoolDemo and reproduce the issue on IoTDB 1.3.2 using the supplied JVM settings and GC evidence. Trace allocations and retention across repeated calls; done means the loop no longer causes old-generation growth leading to a Java heap-space failure.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- java
- Domain
- databases
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100