Repository: incubator-hawq-docs Updated Branches: refs/heads/master 39cd81475 -> 2eb9c1534
Update for current implementation of max_connections (closes #129) Project: http://git-wip-us.apache.org/repos/asf/incubator-hawq-docs/repo Commit: http://git-wip-us.apache.org/repos/asf/incubator-hawq-docs/commit/2eb9c153 Tree: http://git-wip-us.apache.org/repos/asf/incubator-hawq-docs/tree/2eb9c153 Diff: http://git-wip-us.apache.org/repos/asf/incubator-hawq-docs/diff/2eb9c153 Branch: refs/heads/master Commit: 2eb9c153451ab02ca77d3c4a84abc2765a6b0159 Parents: 39cd814 Author: Jane Beckman <[email protected]> Authored: Thu Aug 31 12:47:04 2017 -0700 Committer: David Yozie <[email protected]> Committed: Thu Aug 31 12:47:04 2017 -0700 ---------------------------------------------------------------------- markdown/clientaccess/client_auth.html.md.erb | 27 +++++++--------- ...ubleshooting-connection-problems.html.md.erb | 2 +- .../cli/admin_utilities/hawqinit.html.md.erb | 4 +-- .../reference/guc/guc_category-list.html.md.erb | 2 +- .../guc/parameter_definitions.html.md.erb | 33 ++------------------ 5 files changed, 18 insertions(+), 50 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/incubator-hawq-docs/blob/2eb9c153/markdown/clientaccess/client_auth.html.md.erb ---------------------------------------------------------------------- diff --git a/markdown/clientaccess/client_auth.html.md.erb b/markdown/clientaccess/client_auth.html.md.erb index 33dc717..7dd88ee 100644 --- a/markdown/clientaccess/client_auth.html.md.erb +++ b/markdown/clientaccess/client_auth.html.md.erb @@ -99,27 +99,25 @@ This example shows how to edit the `pg_hba.conf` file of the master to allow rem HAWQ allocates some resources on a per-connection basis, so setting the maximum number of connections allowed is recommended. -To limit the number of active concurrent sessions to your HAWQ system, you can configure the `max_connections` server configuration parameter on master or the `seg_max_connections` server configuration parameter on segments. These parameters are *local* parameters, meaning that you must set them in the `hawq-site.xml` file of all HAWQ instances. +To limit the number of active concurrent sessions to your HAWQ system, you can configure the `max_connections` server configuration parameter on the master instance or the `seg_max_connections` server configuration parameter on segments. -When you set `max_connections`, you must also set the dependent parameter `max_prepared_transactions`. This value must be at least as large as the value of `max_connections`, and all HAWQ instances should be set to the same value. +When you set `max_connections`, you can also set the value for the maximum concurrent connections for the segments by using `seg_max_connections`. Example `$GPHOME/etc/hawq-site.xml` configuration: ``` xml <property> <name>max_connections</name> - <value>500</value> + <value>1280</value> </property> <property> - <name>max_prepared_transactions</name> - <value>1000</value> - </property> - <property> - <name>seg_max_connections</name> - <value>3200</value> + <name>seg_max_connectionss</name> + <value>3000</value> </property> ``` +HAWQ is configured to allow a maximum of 1280 concurrent user connections on the master and 3000 connections on a segment. For best practices, the recommended value for `seg_max_connections` is its default value of 3000. + **Note:** Raising the values of these parameters may cause HAWQ to request more shared memory. To mitigate this effect, consider decreasing other memory-related server configuration parameters such as [gp\_cached\_segworkers\_threshold](../reference/guc/parameter_definitions.html#gp_cached_segworkers_threshold). @@ -129,7 +127,7 @@ You will perform different procedures to set connection-related server configura If you use Ambari to manage your cluster: -1. Set the `max_connections`, `seg_max_connections`, and `max_prepared_transactions` configuration properties via the HAWQ service **Configs > Advanced > Custom hawq-site** drop down. +1. Set the `max_connections` and `seg_max_connections` configuration properties via the HAWQ service **Configs > Advanced > Custom hawq-site** drop down. 2. Select **Service Actions > Restart All** to load the updated configuration. If you manage your cluster from the command line: @@ -140,15 +138,13 @@ If you manage your cluster from the command line: $ source /usr/local/hawq/greenplum_path.sh ``` -2. Use the `hawq config` utility to set the values of the `max_connections`, `seg_max_connections`, and `max_prepared_transactions` parameters to values appropriate for your deployment. For example: +2. Use the `hawq config` utility to set the values of the `max_connections` and `seg_max_connections` parameters to values appropriate for your deployment. For example: ``` bash - $ hawq config -c max_connections -v 100 - $ hawq config -c seg_max_connections -v 6400 - $ hawq config -c max_prepared_transactions -v 200 + $ hawq config -c max_connections -v 1280 + $ hawq config -c seg_max_connections -v 3000 ``` - The value of `max_prepared_transactions` must be greater than or equal to `max_connections`. 5. Load the new configuration values by restarting your HAWQ cluster: @@ -160,7 +156,6 @@ If you manage your cluster from the command line: ``` bash $ hawq config -s max_connections - $ hawq config -s seg_max_connections ``` http://git-wip-us.apache.org/repos/asf/incubator-hawq-docs/blob/2eb9c153/markdown/clientaccess/g-troubleshooting-connection-problems.html.md.erb ---------------------------------------------------------------------- diff --git a/markdown/clientaccess/g-troubleshooting-connection-problems.html.md.erb b/markdown/clientaccess/g-troubleshooting-connection-problems.html.md.erb index 4f7caeb..56ed0ce 100644 --- a/markdown/clientaccess/g-troubleshooting-connection-problems.html.md.erb +++ b/markdown/clientaccess/g-troubleshooting-connection-problems.html.md.erb @@ -28,5 +28,5 @@ A number of things can prevent a client application from successfully connecting |No pg\_hba.conf entry for host or user|To enable HAWQ to accept remote client connections, you must configure your HAWQ master instance so that connections are allowed from the client hosts and database users that will be connecting to HAWQ. This is done by adding the appropriate entries to the pg\_hba.conf configuration file \(located in the master instance's data directory\). For more detailed information, see [Allowing Connections to HAWQ](client_auth.html).| |HAWQ is not running|If the HAWQ master instance is down, users will not be able to connect. You can verify that the HAWQ system is up by running the `hawq state` utility on the HAWQ master host.| |Network problems<br/><br/>Interconnect timeouts|If users connect to the HAWQ master host from a remote client, network problems can prevent a connection \(for example, DNS host name resolution problems, the host system is down, and so on.\). To ensure that network problems are not the cause, connect to the HAWQ master host from the remote client host. For example: `ping hostname`. <br/><br/>If the system cannot resolve the host names and IP addresses of the hosts involved in HAWQ, queries and connections will fail. For some operations, connections to the HAWQ master use `localhost` and others use the actual host name, so you must be able to resolve both. If you encounter this error, first make sure you can connect to each host in your HAWQ array from the master host over the network. In the `/etc/hosts` file of the master and all segments, make sure you have the correct host names and IP addresses for all hosts involved in the HAWQ array. The `127.0.0.1` IP must resolve to `localho st`.| -|Too many clients already|By default, HAWQ is configured to allow a maximum of 200 concurrent user connections on the master and 1280 connections on a segment. A connection attempt that causes that limit to be exceeded will be refused. This limit is controlled by the `max_connections` parameter on the master instance and by the `seg_max_connections` parameter on segment instances. If you change this setting for the master, you must also make appropriate changes at the segments.| +|Too many clients already|By default, HAWQ is configured to allow a maximum of 1280 concurrent user connections on the master and 3000 connections on a segment. A connection attempt that causes that limit to be exceeded will be refused. This limit is controlled by the `max_connections` parameter on the master instance and by the `seg_max_connections` parameter on the segment instances.| |Query failure|Reverse DNS must be configured in your HAWQ cluster network. In cases where reverse DNS has not been configured, failing queries will generate "Failed to reverse DNS lookup for ip \<ip-address\>" warning messages to the HAWQ master node log file. | http://git-wip-us.apache.org/repos/asf/incubator-hawq-docs/blob/2eb9c153/markdown/reference/cli/admin_utilities/hawqinit.html.md.erb ---------------------------------------------------------------------- diff --git a/markdown/reference/cli/admin_utilities/hawqinit.html.md.erb b/markdown/reference/cli/admin_utilities/hawqinit.html.md.erb index 7fdf36b..46069d8 100644 --- a/markdown/reference/cli/admin_utilities/hawqinit.html.md.erb +++ b/markdown/reference/cli/admin_utilities/hawqinit.html.md.erb @@ -51,7 +51,7 @@ where: Â [--lc-monetary=<locale>] [--lc-numeric=<locale>] Â Â [--lc-time=<locale>] Â Â [--bucket_number <number>] -Â Â [--max_connections <number>] Â +Â Â [--max_connections <number>] Â Â [--shared_buffers <number>] ``` @@ -155,7 +155,7 @@ If the primary master fails, the log replication process is shut down. Run the ` <dd>Sets value of `default_hash_table_bucket_number`, which sets the default number of hash buckets for creating virtual segments. This parameter overrides the default value of `default_hash_table_bucket_number` set in `hawq-site.xml` by an Ambari install. If not specified, `hawq init` will use the value in `hawq-site.xml`.</dd> <dt>-\\\-max\_connections=\<number\> </dt> -<dd>Sets the number of client connections allowed to the master. The default is 250.</dd> +<dd>Sets the number of client connections allowed to the master. The default is 1280. Segment connections can be modified at a later time. For more information, see [Configuring Client Authentication](../../../clientaccess/client_auth.html).</dd> <dt>-\\\-shared\_buffers \<number\> </dt> <dd>Sets the number of shared\_buffers to be used when initializing HAWQ.</dd> http://git-wip-us.apache.org/repos/asf/incubator-hawq-docs/blob/2eb9c153/markdown/reference/guc/guc_category-list.html.md.erb ---------------------------------------------------------------------- diff --git a/markdown/reference/guc/guc_category-list.html.md.erb b/markdown/reference/guc/guc_category-list.html.md.erb index d36c1a3..e1755ed 100644 --- a/markdown/reference/guc/guc_category-list.html.md.erb +++ b/markdown/reference/guc/guc_category-list.html.md.erb @@ -75,7 +75,7 @@ These parameters control how clients connect and authenticate to HAWQ. - [listen\_addresses](parameter_definitions.html#listen_addresses) - [max\_connections](parameter_definitions.html#max_connections) -- [max\_prepared\_transactions](parameter_definitions.html#max_prepared_transactions) +- [seg\_max\_connections](parameter_definitions.html#seg_max_connections) - [superuser\_reserved\_connections](parameter_definitions.html#superuser_reserved_connections) - [tcp\_keepalives\_count](parameter_definitions.html#tcp_keepalives_count) - [tcp\_keepalives\_idle](parameter_definitions.html#tcp_keepalives_idle) http://git-wip-us.apache.org/repos/asf/incubator-hawq-docs/blob/2eb9c153/markdown/reference/guc/parameter_definitions.html.md.erb ---------------------------------------------------------------------- diff --git a/markdown/reference/guc/parameter_definitions.html.md.erb b/markdown/reference/guc/parameter_definitions.html.md.erb index 6167958..d4968e0 100644 --- a/markdown/reference/guc/parameter_definitions.html.md.erb +++ b/markdown/reference/guc/parameter_definitions.html.md.erb @@ -422,8 +422,6 @@ Descriptions of the HAWQ server configuration parameters listed alphabetically. - **[max\_locks\_per\_transaction](../../reference/guc/parameter_definitions.html#max_locks_per_transaction)** -- **[max\_prepared\_transactions](../../reference/guc/parameter_definitions.html#max_prepared_transactions)** - - **[max\_stack\_depth](../../reference/guc/parameter_definitions.html#max_stack_depth)** - **[optimizer](../../reference/guc/parameter_definitions.html#optimizer)** @@ -2609,7 +2607,7 @@ Sets the maximum number of append-only relations that can be written to or loade ## <a name="max_connections"></a>max\_connections -The maximum number of concurrent connections allowed on master. In a HAWQ system, user client connections go through the HAWQ master instance only. Segment instances should allow 5-10 times the amount as the master. When you increase this parameter, you must increase [max\_prepared\_transactions](#max_prepared_transactions) as well. For more information about limiting concurrent connections, see [Configuring Client Authentication](../../clientaccess/client_auth.html). +The maximum number of concurrent connections allowed on master. In a HAWQ system, user client connections go through the HAWQ master instance. Segment instances can override this value by specifying a different value in `seg_max_connections`. The default value for segment connections is 3000, but can be up to 10 times the number of connections allowed for the master instance. For more information about limiting concurrent connections, see [Configuring Client Authentication](../../clientaccess/client_auth.html). Increasing this parameter may cause HAWQ to request more shared memory. See [shared\_buffers](#shared_buffers) for information about HAWQ server instance shared memory buffers. @@ -2677,32 +2675,7 @@ The shared lock table is created with room to describe locks on *max\_locks\_per |-------------|---------|------------------------| | integer | 128 | local, system, restart | -## <a name="max_prepared_transactions"></a>max\_prepared\_transactions - -Sets the maximum number of transactions that can be in the prepared state simultaneously. HAWQ uses prepared transactions internally to ensure data integrity across the segments. This value must be at least as large as the value of [max\_connections](#max_connections) on the master. Segment instances should be set to the same value as the master. -<table> -<colgroup> -<col width="33%" /> -<col width="33%" /> -<col width="33%" /> -</colgroup> -<thead> -<tr class="header"> -<th>Value Range</th> -<th>Default</th> -<th>Set Classifications</th> -</tr> -</thead> -<tbody> -<tr class="odd"> -<td>integer</td> -<td>250 on master -<p>250 on segments</p></td> -<td>local, system, restart</td> -</tr> -</tbody> -</table> ## <a name="max_stack_depth"></a>max\_stack\_depth @@ -2992,7 +2965,7 @@ Specifies the order in which schemas are searched when an object is referenced b ## <a name="seg_max_connections"></a>seg\_max\_connections -The maximum number of concurrent connections on a segment. In a HAWQ system, user client connections go through the HAWQ master instance only. Segment instances should allow 5-10 times the amount of connections allowed on the master (see [max\_connections](#max_connections).) When you increase this parameter, you must increase [max\_prepared\_transactions](#max_prepared_transactions) as well. For more information about limiting concurrent connections, see [Configuring Client Authentication](../../clientaccess/client_auth.html). +The maximum number of concurrent connections on a segment. In a HAWQ system, user client connections go through the HAWQ master instance. However, `seg_max_connections` overwrites the master instance value to allow the segments to use a different number of concurrent connections. The default value for best practices is 3000 connections. Segment instances can allow up to 10 times the amount of connections allowed on the master (see [max\_connections](#max_connections).) For more information about limiting concurrent connections, see [Configuring Client Authentication](../../clientaccess/client_auth.html). Increasing this parameter may cause HAWQ to request more shared memory. See [shared\_buffers](#shared_buffers) for information about HAWQ server instance shared memory buffers. @@ -3012,7 +2985,7 @@ Increasing this parameter may cause HAWQ to request more shared memory. See [sha <tbody> <tr class="odd"> <td>integer (240-<em>n</em>)</td> -<td><p>1280</p></td> +<td><p>3000</p></td> <td>local, system, restart</td> </tr> </tbody>
