fix(java-client): fix client renew TGT thread leak when request table doesnt exist

[Samunroyu]

In the Kerberos environment, java client will check TGT and relogin kerberos if needed every 10 seconds by a thread. But when client requests table which doesnt exist will cause threads leak.

The root cause this problem is when Pegasus client close the client but don't close TGT thread pool.

This patch adds KerberosProtocol close function.

[shalk]

Handle Exception is a good choice. Exception will make the schedule job not schedule again

But i am not quite understand the main cause about daemon
I don't kown the relatetionship between daemon thread with exception handler @Samunroyu

if you set daemon false, you should shutdown the threadpool when client jvm shutdown.

[Apache9]

Handle Exception is a good choice. Exception will make the schedule job not schedule again

But i am not quite understand the main cause about daemon I don't kown the relatetionship between daemon thread with exception handler @Samunroyu

if you set daemon false, you should shutdown the threadpool when client jvm shutdown.

I‘ve talked with @Samunroyu offline, the root cause here is we do not have a close method for KerberosProtocol class, so if we create the client many time due to kerberos authentication error, although we have already closed all the created client, the KerberosProtocol will not be closed, so the ExecutorService will be leaked and cause too many threads.

[shalk]

Handle Exception is a good choice. Exception will make the schedule job not schedule again But i am not quite understand the main cause about daemon I don't kown the relatetionship between daemon thread with exception handler @Samunroyu if you set daemon false, you should shutdown the threadpool when client jvm shutdown.

I‘ve talked with @Samunroyu offline, the root cause here is we do not have a close method for KerberosProtocol class, so if we create the client many time due to kerberos authentication error, although we have already closed all the created client, the KerberosProtocol will not be closed, so the ExecutorService will be leaked and cause too many threads.

It make sense. I get the case about thread leak.

if the pr finish and ci pass, click request , i will review again @Samunroyu