docs/geode-native-docs-cpp/preserving-data/sending-periodic-ack.html.md.erb - geode-native - Git at Google

 ---
 title:  Sending Periodic Acknowledgment
 ---

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 Servers use periodic acknowledgment to reduce the likelihood of duplicate notifications, and to reduce resource usage.

 <a id="concept_868B8082463846DE9F35BBEA56105C82__section_D4375BCCF8A2426BA58073B9549B6F04"></a>
 When redundancy is enabled for high availability and `redundancy-level` is set to 1 or higher, clients send (and servers expect) periodic acknowledgment messages at configurable intervals for notifications they have received. A periodic ack is not sent by the client if there are no unacknowledged notifications at the time.

 Use the following system properties in the `geode.properties` file to configure periodic ack.

 <table>
 <colgroup>
 <col width="50%" />
 <col width="50%" />
 </colgroup>
 <tbody>
 <tr class="odd">
 <td><code class="ph codeph">notify-ack-interval</code></td>
 <td><p>Minimum period between two consecutive acknowledgment messages sent from the client to the server. The default setting (in seconds) is 10.</p></td>
 </tr>
 <tr class="even">
 <td><code class="ph codeph">notify-dupcheck-life</code></td>
 <td><p>Minimum time a client continues to track a notification source for duplicates when no new notifications arrive before expiring it. The default setting (in seconds) is 300.</p></td>
 </tr>
 </tbody>
 </table>

 The Pool API also provides attributes to configure periodic ack and duplicate message tracking timeout. See `subscription-message-tracking-timeout` and `subscription-ack-interval` in the list of pool attributes under [Configuring Pools for Servers or Locators](../connection-pools/configuring-pools.html#configuring-pools).
	---
	title: Sending Periodic Acknowledgment
	---

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	Licensed to the Apache Software Foundation (ASF) under one or more
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	this work for additional information regarding copyright ownership.
	The ASF licenses this file to You under the Apache License, Version 2.0
	(the "License"); you may not use this file except in compliance with
	the License. You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
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	Servers use periodic acknowledgment to reduce the likelihood of duplicate notifications, and to reduce resource usage.

	<a id="concept_868B8082463846DE9F35BBEA56105C82__section_D4375BCCF8A2426BA58073B9549B6F04"></a>
	When redundancy is enabled for high availability and `redundancy-level` is set to 1 or higher, clients send (and servers expect) periodic acknowledgment messages at configurable intervals for notifications they have received. A periodic ack is not sent by the client if there are no unacknowledged notifications at the time.

	Use the following system properties in the `geode.properties` file to configure periodic ack.

	<table>
	<colgroup>
	<col width="50%" />
	<col width="50%" />
	</colgroup>
	<tbody>
	<tr class="odd">
	<td><code class="ph codeph">notify-ack-interval</code></td>
	<td><p>Minimum period between two consecutive acknowledgment messages sent from the client to the server. The default setting (in seconds) is 10.</p></td>
	</tr>
	<tr class="even">
	<td><code class="ph codeph">notify-dupcheck-life</code></td>
	<td><p>Minimum time a client continues to track a notification source for duplicates when no new notifications arrive before expiring it. The default setting (in seconds) is 300.</p></td>
	</tr>
	</tbody>
	</table>

	The Pool API also provides attributes to configure periodic ack and duplicate message tracking timeout. See `subscription-message-tracking-timeout` and `subscription-ack-interval` in the list of pool attributes under [Configuring Pools for Servers or Locators](../connection-pools/configuring-pools.html#configuring-pools).