# Elasticsearch warning logs while stopping tomcat
**URL:** https://discuss.elastic.co/t/elasticsearch-warning-logs-while-stopping-tomcat/295845
**Category:** Elasticsearch
**Tags:** language-clients
**Created:** [January 31, 2022, 1:23pm UTC](https://discuss.elastic.co/t/elasticsearch-warning-logs-while-stopping-tomcat/295845 "2022-01-31T13:23:24Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Ram\_N](https://discuss.elastic.co/u/Ram_N)
#### Post date: [January 31, 2022, 1:23pm UTC](https://discuss.elastic.co/t/elasticsearch-warning-logs-while-stopping-tomcat/295845/1 "2022-01-31T13:23:24Z")
Hi
Im using ELK 7.10.2 and uses below code to connect to Elasticsearch using java
```auto
Settings settings = Settings.builder()
.put("cluster.name", elkUtil.getClusterName(Constants.ELASTICSEARCH_YAML_PATH)).build();
esClient = new PreBuiltTransportClient(settings)
.addTransportAddress(new TransportAddress(InetAddress.getByName(host), 9300));
```
While stopping spring boot, Im calling Client.close as below
```auto
public synchronized void shutdownES(){
esClient.close();
logger.info("Remote connection closed to ES");
}
```
But still Tomcat logs throw below warning
```auto
an 31, 2022 6:39:46 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
WARNING: The web application [ROOT] appears to have started a thread named [elasticsearch[_client_][generic][T#2]] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
sun.misc.Unsafe.park(Native Method)
java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
java.util.concurrent.LinkedTransferQueue.awaitMatch(LinkedTransferQueue.java:737)
java.util.concurrent.LinkedTransferQueue.xfer(LinkedTransferQueue.java:647)
java.util.concurrent.LinkedTransferQueue.take(LinkedTransferQueue.java:1269)
java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
java.lang.Thread.run(Thread.java:748)
Jan 31, 2022 6:39:46 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
WARNING: The web application [ROOT] appears to have started a thread named [elasticsearch[_client_][transport_worker][T#2]] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)
sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
sun.nio.ch.SelectorImpl.select(SelectorImpl.java:101)
io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:803)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:457)
io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
java.lang.Thread.run(Thread.java:748)
Jan 31, 2022 6:39:46 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
WARNING: The web application [ROOT] appears to have started a thread named [elasticsearch[_client_][generic][T#3]] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
sun.misc.Unsafe.park(Native Method)
java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
java.util.concurrent.LinkedTransferQueue.awaitMatch(LinkedTransferQueue.java:737)
java.util.concurrent.LinkedTransferQueue.xfer(LinkedTransferQueue.java:647)
java.util.concurrent.LinkedTransferQueue.take(LinkedTransferQueue.java:1269)
java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
java.lang.Thread.run(Thread.java:748)
```
What am I doing wrong here? Can someone please help
---
### Author:  [@dadoonet](https://discuss.elastic.co/u/dadoonet)
#### Post date: [January 31, 2022, 3:21pm UTC](https://discuss.elastic.co/t/elasticsearch-warning-logs-while-stopping-tomcat/295845/2 "2022-01-31T15:21:39Z")
Don't use the TransportClient. It has been deprecated.
Please also upgrade your cluster to 7.16.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [February 28, 2022, 3:22pm UTC](https://discuss.elastic.co/t/elasticsearch-warning-logs-while-stopping-tomcat/295845/3 "2022-02-28T15:22:05Z")
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