docs/geode-native-docs-cpp/regions/consistency-checking-in-regions.html.md.erb - geode-native - Git at Google

 ---
 title:  Region Consistency
 ---

 <!--
 Licensed to the Apache Software Foundation (ASF) under one or more
 contributor license agreements.  See the NOTICE file distributed with
 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,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 -->

 <%=vars.product_name%> ensures that all copies of a region eventually reach a consistent state on all members and clients that host the region.

 By default <%=vars.product_name%> members perform consistency checks when they apply updates to a distributed region, in order to ensure that all copies of the region eventually become consistent on all <%=vars.product_name%> members and client caches that host the region. Different types of region ensure consistency using different techniques. However, when consistency checking is enabled (the default) all entries in a region require additional overhead in order to store version and timestamp information.

 Although a region must have the same consistency checking configuration on all <%=vars.product_name%> members that host the region, you can optionally disable consistency checking in a client cache region while leaving consistency checking enabled for the region on <%=vars.product_name%> members. This configuration may be necessary in certain cases where the client must view all updates to a given region, even when <%=vars.product_name%> members discards an update in order to preserve region consistency.

 See [Consistency for Region Updates](geodeman/developing/distributed_regions/region_entry_versions.html#topic_CF2798D3E12647F182C2CEC4A46E2045) in the server's documentation for more information.

 ## <a id="concept_77340A4999AC4861972A0EE10303E557__section_167CD194A5374C64B4064783490F3EA8" class="no-quick-link"></a>Client Overhead for Consistency Checks

 In the client regions, the overhead for performing consistency check is an additional 11 bytes per region entry. This overhead is slightly smaller than the overhead required to provide consistency checking on server-side region entries.

 If you cannot support the additional overhead in your deployment, you can disable consistency checks by setting the region attribute `concurrency-checks-enabled` to false for each region hosted by your client.
	---
	title: Region Consistency
	---

	<!--
	Licensed to the Apache Software Foundation (ASF) under one or more
	contributor license agreements. See the NOTICE file distributed with
	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,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
	-->

	<%=vars.product_name%> ensures that all copies of a region eventually reach a consistent state on all members and clients that host the region.

	By default <%=vars.product_name%> members perform consistency checks when they apply updates to a distributed region, in order to ensure that all copies of the region eventually become consistent on all <%=vars.product_name%> members and client caches that host the region. Different types of region ensure consistency using different techniques. However, when consistency checking is enabled (the default) all entries in a region require additional overhead in order to store version and timestamp information.

	Although a region must have the same consistency checking configuration on all <%=vars.product_name%> members that host the region, you can optionally disable consistency checking in a client cache region while leaving consistency checking enabled for the region on <%=vars.product_name%> members. This configuration may be necessary in certain cases where the client must view all updates to a given region, even when <%=vars.product_name%> members discards an update in order to preserve region consistency.

	See [Consistency for Region Updates](geodeman/developing/distributed_regions/region_entry_versions.html#topic_CF2798D3E12647F182C2CEC4A46E2045) in the server's documentation for more information.

	## <a id="concept_77340A4999AC4861972A0EE10303E557__section_167CD194A5374C64B4064783490F3EA8" class="no-quick-link"></a>Client Overhead for Consistency Checks

	In the client regions, the overhead for performing consistency check is an additional 11 bytes per region entry. This overhead is slightly smaller than the overhead required to provide consistency checking on server-side region entries.

	If you cannot support the additional overhead in your deployment, you can disable consistency checks by setting the region attribute `concurrency-checks-enabled` to false for each region hosted by your client.