我们有一个3节点的Kafka集群部署,其中包含5个主题,每个主题6个分区。我们已经配置了复制因子= 3,我们看到了一个非常奇怪的问题,即文件描述符的数量已经超过了ulimit(对于我们的应用程序是50K)
As per the lsof command and our analysis
1. there have 15K established connection from kafka producer/consumer towards broker and at the same time in thread dump we have observed thousands of entry for kafka 'admin-client-network-thread'
admin-client-network-thread" #224398 daemon prio=5 os_prio=0 tid=0x00007f12ca119800 nid=0x5363 runnable [0x00007f12c4db8000]
java.lang.Thread.State: RUNNABLE
at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)
at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
- locked <0x00000005e0603238> (a sun.nio.ch.Util$3)
- locked <0x00000005e0603228> (a java.util.Collections$unmodifiableSet)
- locked <0x00000005e0602f08> (a sun.nio.ch.EPollSelectorImpl)
at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
at org.apache.kafka.common.network.Selector.select(Selector.java:672)
at org.apache.kafka.common.network.Selector.poll(Selector.java:396)
at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:460)
at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:238)
- locked <0x00000005e0602dc0> (a org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient)
at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:214)
at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:205)
at kafka.admin.AdminClient$$anon$1.run(AdminClient.scala:61)
at java.lang.Thread.run(Thread.java:748)
2. As per the lsof output,We have observed 35K entry for pipe and event poll
java 5441 app 374r FIFO 0,9 0t0 22415240 pipe
java 5441 app 375w FIFO 0,9 0t0 22415240 pipe
java 5441 app 376u a_inode 0,10 0 6379 [eventpoll]
java 5441 app 377r FIFO 0,9 0t0 22473333 pipe
java 5441 app 378r FIFO 0,9 0t0 28054726 pipe
java 5441 app 379r FIFO 0,9 0t0 22415241 pipe
java 5441 app 380w FIFO 0,9 0t0 22415241 pipe
java 5441 app 381u a_inode 0,10 0 6379 [eventpoll]
java 5441 app 382w FIFO 0,9 0t0 22473333 pipe
java 5441 app 383u a_inode 0,10 0 6379 [eventpoll]
java 5441 app 384u a_inode 0,10 0 6379 [eventpoll]
java 5441 app 385r FIFO 0,9 0t0 40216087 pipe
java 5441 app 386r FIFO 0,9 0t0 22483470 pipe
Setup details :-
apache kafka client :- 1.0.1
Kafka version :- 1.0.1
Open JDK :- java-1.8.0-openjdk-1.8.0.222.b10-1
CentOS version :- CentOS Linux release 7.6.1810
Note:- After restarted VM file descriptor count was able to clear and come to normal count as 1000
then after few second file descriptor count started to increase and it will reach to 50K (limit) after
1-week in Idle scenarios.