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Posted to commits@impala.apache.org by jo...@apache.org on 2019/07/26 21:40:32 UTC
[impala] 02/08: IMPALA-8616: [DOCS] Document
--disconnected_session_timeout flag for HS2
This is an automated email from the ASF dual-hosted git repository.
joemcdonnell pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/impala.git
commit ddf92017668a9e4a0935a3643c27115522b845c1
Author: Alex Rodoni <ar...@cloudera.com>
AuthorDate: Tue Jul 23 16:36:37 2019 -0700
IMPALA-8616: [DOCS] Document --disconnected_session_timeout flag for HS2
Change-Id: I2c178116ec9cb8abf619c9fdcfb2697bcfb1de5c
Reviewed-on: http://gerrit.cloudera.org:8080/13903
Tested-by: Impala Public Jenkins <im...@cloudera.com>
Reviewed-by: Thomas Tauber-Marshall <tm...@cloudera.com>
---
docs/topics/impala_client.xml | 67 +++++++++++++++++++++++++++++--------------
1 file changed, 46 insertions(+), 21 deletions(-)
diff --git a/docs/topics/impala_client.xml b/docs/topics/impala_client.xml
index 099ba4a..b17deea 100644
--- a/docs/topics/impala_client.xml
+++ b/docs/topics/impala_client.xml
@@ -84,20 +84,30 @@ under the License.
<dlentry>
<dt>
- --fe_service_threads
+ --accepted_client_cnxn_timeout
</dt>
<dd>
- Specifies the maximum number of concurrent client connections allowed. The default
- value is 64 with which 64 queries can run simultaneously.
+ Controls how Impala treats new connection requests if it has run out of the number
+ of threads configured by <codeph>--fe_service_threads</codeph>.
<p>
- If you have more clients trying to connect to Impala than the value of this
- setting, the later arriving clients have to wait for the duration specified by
- <codeph>--accepted_client_cnxn_timeout</codeph>. You can increase this value to
- allow more client connections. However, a large value means more threads to be
- maintained even if most of the connections are idle, and it could negatively
- impact query latency. Client applications should use the connection pool to avoid
- need for large number of sessions.
+ If <codeph>--accepted_client_cnxn_timeout > 0</codeph>, new connection requests
+ are rejected if Impala can't get a server thread within the specified (in seconds)
+ timeout.
+ </p>
+
+ <p>
+ If <codeph>--accepted_client_cnxn_timeout=0</codeph>, i.e. no timeout, clients
+ wait indefinitely to open the new session until more threads are available.
+ </p>
+
+ <p>
+ The default timeout is 5 minutes.
+ </p>
+
+ <p>
+ The timeout applies only to client facing thrift servers, i.e., HS2 and Beeswax
+ servers.
</p>
</dd>
@@ -106,30 +116,45 @@ under the License.
<dlentry>
<dt>
- --accepted_client_cnxn_timeout
+ --disconnected_session_timeout
</dt>
<dd>
- Controls how Impala treats new connection requests if it has run out of the number
- of threads configured by <codeph>--fe_service_threads</codeph>.
+ When a HiveServer2 session has had no open connections for longer than this value,
+ the session will be closed, and any associated queries will be unregistered.
<p>
- If <codeph>--accepted_client_cnxn_timeout > 0</codeph>, new connection requests
- are rejected if Impala can't get a server thread within the specified (in seconds)
- timeout.
+ Specify the value in hours.
</p>
<p>
- If <codeph>--accepted_client_cnxn_timeout=0</codeph>, i.e. no timeout, clients
- wait indefinitely to open the new session until more threads are available.
+ The default value is 1 hour.
</p>
<p>
- The default timeout is 5 minutes.
+ This flag does not apply to Beeswax clients. When a Beeswax client connection is
+ closed, Impala closes the session associated with that connection.
</p>
+ </dd>
+
+ </dlentry>
+
+ <dlentry>
+
+ <dt>
+ --fe_service_threads
+ </dt>
+ <dd>
+ Specifies the maximum number of concurrent client connections allowed. The default
+ value is 64 with which 64 queries can run simultaneously.
<p>
- The timeout applies only to client facing thrift servers, i.e., HS2 and Beeswax
- servers.
+ If you have more clients trying to connect to Impala than the value of this
+ setting, the later arriving clients have to wait for the duration specified by
+ <codeph>--accepted_client_cnxn_timeout</codeph>. You can increase this value to
+ allow more client connections. However, a large value means more threads to be
+ maintained even if most of the connections are idle, and it could negatively
+ impact query latency. Client applications should use the connection pool to avoid
+ need for large number of sessions.
</p>
</dd>