CouchBaseTemplate Connection issue - spring-mvc

Question

I have the Following CouchBase Template Bean:
#PostConstruct
public void initIt() throws Exception {
if(couchbaseDisabled)
return;
couchbaseClient= new CouchbaseClient(
bootstrapUris(Arrays.asList(hosts.split(","))),
CouchbaseConstants.BUCKET,
""
);
couchbaseTemplate();
}
public void couchbaseTemplate() throws Exception {
logger.info("Enabling CouchBase Template");
couchbaseTemplate= new CouchbaseTemplate(couchbaseClient);
//couchbaseTemplate.
}
and
#PreDestroy
public void cleanup() throws Exception {
logger.info("Closing couchbase connection.");
if (couchbaseClient != null) {
couchbaseClient.shutdown();
couchbaseTemplate=null;
couchbaseClient=null;
}
}
While the Server is being Shut Down i am geting the Following Logs:
SEVERE: The web application [] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Jan 8, 2016 4:57:24 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal#40c94525]) and a value of type [com.couchbase.client.deps.io.netty.util.internal.InternalThreadLocalMap] (value [com.couchbase.client.deps.io.netty.util.internal.InternalThreadLocalMap#5ddaa15d]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Jan 8, 2016 4:57:24 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal#40c94525]) and a value of type [com.couchbase.client.deps.io.netty.util.internal.InternalThreadLocalMap] (value [com.couchbase.client.deps.io.netty.util.internal.InternalThreadLocalMap#3c9810ce]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Jan 8, 2016 4:57:24 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal#40c94525]) and a value of type [com.couchbase.client.deps.io.netty.util.internal.InternalThreadLocalMap] (value [com.couchbase.client.deps.io.netty.util.internal.InternalThreadLocalMap#23776376]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Jan 8, 2016 4:57:24 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [] created a ThreadLocal with key of type [java.lang.ThreadLocal] (value [java.lang.ThreadLocal#40c94525]) and a value of type [com.couchbase.client.deps.io.netty.util.internal.InternalThreadLocalMap] (value [com.couchbase.client.deps.io.netty.util.internal.InternalThreadLocalMap#7322ea2a]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
Jan 8, 2016 4:57:32 PM org.apache.coyote.http11.Http11Protocol destroy
INFO: Stopping Coyote HTTP/1.1 on http-8099
What can be Done Here?

Answer 1

Ok so you have both SDK 1.4.x and 2.x running in your application (since you have com.couchbase.client:java-client in your pom).
The thread leak message comes from the later. You must have instantiated a Cluster somewhere (as in com.couchbase.client.java.Cluster).
Make sure to also clean it up at the end of the application's lifecycle by calling cluster.disconnect() (I guess from a #PreDestroy method, as you did for the CouchbaseClient).
If you also created a custom CouchbaseEnvironment, you have to also properly shut it down (in the same method as the Cluster cleanup) by calling environment.shutdownAsync().toBlocking().single().
Make sure to use the latest version of the 2.x SDK as some older versions had bugs relative to proper thread cleanup on shutdown (see JCBC-773 and JVMCBC-251 issues).