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Posted to issues-all@impala.apache.org by "Ivan Cho (Jira)" <ji...@apache.org> on 2020/01/09 04:10:00 UTC

[jira] [Updated] (IMPALA-9283) impala can not release the JDBC connection automatically

     [ https://issues.apache.org/jira/browse/IMPALA-9283?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ivan Cho updated IMPALA-9283:
-----------------------------
    Description: 
h3. It looks like that impala can not release the JDBC connection automatically ,
 especially when jdbc client application crash down while running sql or with bed practice that have not call \{res.close()/stmt.close()/con.close()} explicitly .
h3. Here are some useful information:
h2. 1 : the number of active connection has increased all the time utill we restarted the whole impala cluster (regulerly at midnight). see below
 !1.png|width=1623,height=582!
h2. !1-1.png!
h2. 2 : there are three main type of jdbc client applications: streamsets/hue/java .  below is streamsets use case:
 !2.png!

!2-1.png!
h2. !2-2.png!   
h2. 3 : I did two jdbc tests with java application. 
 Test 1 started 900 threads , and did not close connection resource after complete qurey sql , so the number of connection did not decrease 
 Inversely , Test 2 started 500 threads , just close connection resource after complete qurey sql , so the number of connection decrease. see below
 !3.png!
 ps: attachment are impalad_flags

  was:
It looks like that impala can not release the JDBC connection automatically ,
especially when jdbc client application crash down while running sql or with bed practice that have not call \{res.close()/stmt.close()/con.close()} explicitly .

Here are some useful information:

1 : the number of active connection has increased all the time utill we restarted the whole impala cluster (regulerly at midnight). see below
!1.png|width=1623,height=582!

!1-1.png!
2 : there are three main type of jdbc client applications: streamsets/hue/java .  below is streamsets use case:
!2.png!

!2-1.png!

!2-2.png!   
3 : I did two jdbc tests with java application. 
 Test 1 started 900 threads , and did not close connection resource after complete qurey sql , so the number of connection did not decrease 
 Inversely , Test 2 started 500 threads , just close connection resource after complete qurey sql , so the number of connection decrease. see below
!3.png!
ps: attachment are impalad_flags


>  impala can not release the JDBC connection automatically
> ---------------------------------------------------------
>
>                 Key: IMPALA-9283
>                 URL: https://issues.apache.org/jira/browse/IMPALA-9283
>             Project: IMPALA
>          Issue Type: Bug
>          Components: Backend
>    Affects Versions: Impala 2.12.0
>            Reporter: Ivan Cho
>            Priority: Major
>         Attachments: 1-1.png, 1.png, 2-1.png, 2-2.png, 2.png, 3.png, impalad_flags(coordinator-only), impalad_flags(executor-only)
>
>
> h3. It looks like that impala can not release the JDBC connection automatically ,
>  especially when jdbc client application crash down while running sql or with bed practice that have not call \{res.close()/stmt.close()/con.close()} explicitly .
> h3. Here are some useful information:
> h2. 1 : the number of active connection has increased all the time utill we restarted the whole impala cluster (regulerly at midnight). see below
>  !1.png|width=1623,height=582!
> h2. !1-1.png!
> h2. 2 : there are three main type of jdbc client applications: streamsets/hue/java .  below is streamsets use case:
>  !2.png!
> !2-1.png!
> h2. !2-2.png!   
> h2. 3 : I did two jdbc tests with java application. 
>  Test 1 started 900 threads , and did not close connection resource after complete qurey sql , so the number of connection did not decrease 
>  Inversely , Test 2 started 500 threads , just close connection resource after complete qurey sql , so the number of connection decrease. see below
>  !3.png!
>  ps: attachment are impalad_flags



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