Vertx program memory keeps growing - vert.x

Question

I used the top command to check on the Linux server, and found that the Memory of the deployed Vertx program has been increasing. I printed the Memory usage with Native Memory Tracking, and found that the Internal Memory has been increasing.I didn't manually allocate out of heap memory in the code.
Native Memory Tracking:
Total: reserved=7595MB, committed=6379MB
Java Heap (reserved=4096MB, committed=4096MB)
(mmap: reserved=4096MB, committed=4096MB)
Class (reserved=1101MB, committed=86MB)
(classes #12776)
(malloc=7MB #18858)
(mmap: reserved=1094MB, committed=79MB)
Thread (reserved=122MB, committed=122MB)
(thread #122)
(stack: reserved=121MB, committed=121MB)
Code (reserved=253MB, committed=52MB)
(malloc=9MB #12566)
(mmap: reserved=244MB, committed=43MB)
GC (reserved=155MB, committed=155MB)
(malloc=6MB #302)
(mmap: reserved=150MB, committed=150MB)
Internal (reserved=1847MB, committed=1847MB)
(malloc=1847MB #35973)
Symbol (reserved=17MB, committed=17MB)
(malloc=14MB #137575)
(arena=3MB #1)
Native Memory Tracking (reserved=4MB, committed=4MB)
(tracking overhead=3MB)
vertx version:3.9.8
Cluster:Hazelcast
startup script:su web -s /bin/bash -c "/usr/bin/nohup /usr/bin/java -XX:NativeMemoryTracking=detail -javaagent:../target/showbiz-server-game-1.0-SNAPSHOT-fat.jar -javaagent:../../quasar-core-0.8.0.jar=b -Dvertx.hazelcast.config=/data/appdata/webdata/Project/config/cluster.xml -jar -Xms4G -Xmx4G -XX:-OmitStackTraceInFastThrow ../target/server-1.0-SNAPSHOT-fat.jar start-Dvertx-id=server -conf application-conf.json -Dlog4j.configurationFile=log4j2_logstash.xml -cluster >nohup.out 2>&1 &"

Answer 1

If your producers are much faster than your consumers, and back pressure isn't handled properly, it's possible to have memory that keeps increasing.
Also, this could vary depending on how the code is written.
This similar reported issue could be of help and consider exploring writeStream too.