topic Re: trouble getting content up on both sides of Alfresco in Alfresco Archive https://connect.hyland.com/t5/alfresco-archive/trouble-getting-content-up-on-both-sides-of-alfresco/m-p/188373#M141503 <HTML><HEAD></HEAD><BODY><SPAN>This approach is unlikely to work for a number of reasons:</SPAN><BR /><OL style="list-style-type:decimal;"><LI>As you've discovered, without cluster-wide cache coherency (which is achieved via EHCache configuration) content updates don't appear right away on anything but the node where the update took place.&nbsp; This problem is serious enough that it can lead to corruption if not corrected.</LI><BR /><LI>The latencies inherent in replication (be it via rsync or Oracle or something else) are likely to cause further problems, even if the cache coherency problem is resolved.&nbsp; This is because EHCache distributes events synchronously with respect to each Alfresco transaction, whereas replication is likely to be asynchronous ie. executes some time (perhaps even minutes) after the Alfresco transaction has completed.&nbsp; During that window the cache and replicated persistent storage (Oracle + filesystem) on each recipient node will be out of sync, causing all manner of unexpected behaviour.</LI><BR /><LI>Directly manipulating the Alfresco database and filesystem while Alfresco is running is guaranteed to cause any number of problems (including corruption, excessive blocking and sporadic lock related errors, and poor performance).&nbsp; Alfresco <EM>requires</EM> exclusive access to both.</LI></OL><SPAN>As described at </SPAN><A href="http://wiki.alfresco.com/wiki/Cluster_Configuration_V2.1.3_and_Later" rel="nofollow noopener noreferrer">http://wiki.alfresco.com/wiki/Cluster_Configuration_V2.1.3_and_Later</A><SPAN>, Alfresco clustering fundamentally requires a single logical database and filesystem across the cluster.&nbsp; These may in fact be clustered themselves, but both components </SPAN><EM>must</EM><SPAN> act as though they are each a single system.&nbsp; Replication doesn't provide that guarantee, primarily due to the latencies involved.</SPAN><BR /><BR /><SPAN>Cheers,</SPAN><BR /><SPAN>Peter</SPAN></BODY></HTML> Thu, 11 Sep 2008 04:28:35 GMT pmonks 2008-09-11T04:28:35Z trouble getting content up on both sides of Alfresco https://connect.hyland.com/t5/alfresco-archive/trouble-getting-content-up-on-both-sides-of-alfresco/m-p/188372#M141502 We are having trouble getting content to show up on both sides of our Alfresco setup.&nbsp; - Alfresco 3.0.0 (schema 128)&nbsp; - Geographically separated Oracle 10g databases in which our Alfresco schema is eing replicated via Oracle streams&nbsp; - Geographically separated Alfresco application servers running To Tue, 09 Sep 2008 19:46:22 GMT https://connect.hyland.com/t5/alfresco-archive/trouble-getting-content-up-on-both-sides-of-alfresco/m-p/188372#M141502 gendhar 2008-09-09T19:46:22Z Re: trouble getting content up on both sides of Alfresco https://connect.hyland.com/t5/alfresco-archive/trouble-getting-content-up-on-both-sides-of-alfresco/m-p/188373#M141503 <HTML><HEAD></HEAD><BODY><SPAN>This approach is unlikely to work for a number of reasons:</SPAN><BR /><OL style="list-style-type:decimal;"><LI>As you've discovered, without cluster-wide cache coherency (which is achieved via EHCache configuration) content updates don't appear right away on anything but the node where the update took place.&nbsp; This problem is serious enough that it can lead to corruption if not corrected.</LI><BR /><LI>The latencies inherent in replication (be it via rsync or Oracle or something else) are likely to cause further problems, even if the cache coherency problem is resolved.&nbsp; This is because EHCache distributes events synchronously with respect to each Alfresco transaction, whereas replication is likely to be asynchronous ie. executes some time (perhaps even minutes) after the Alfresco transaction has completed.&nbsp; During that window the cache and replicated persistent storage (Oracle + filesystem) on each recipient node will be out of sync, causing all manner of unexpected behaviour.</LI><BR /><LI>Directly manipulating the Alfresco database and filesystem while Alfresco is running is guaranteed to cause any number of problems (including corruption, excessive blocking and sporadic lock related errors, and poor performance).&nbsp; Alfresco <EM>requires</EM> exclusive access to both.</LI></OL><SPAN>As described at </SPAN><A href="http://wiki.alfresco.com/wiki/Cluster_Configuration_V2.1.3_and_Later" rel="nofollow noopener noreferrer">http://wiki.alfresco.com/wiki/Cluster_Configuration_V2.1.3_and_Later</A><SPAN>, Alfresco clustering fundamentally requires a single logical database and filesystem across the cluster.&nbsp; These may in fact be clustered themselves, but both components </SPAN><EM>must</EM><SPAN> act as though they are each a single system.&nbsp; Replication doesn't provide that guarantee, primarily due to the latencies involved.</SPAN><BR /><BR /><SPAN>Cheers,</SPAN><BR /><SPAN>Peter</SPAN></BODY></HTML> Thu, 11 Sep 2008 04:28:35 GMT https://connect.hyland.com/t5/alfresco-archive/trouble-getting-content-up-on-both-sides-of-alfresco/m-p/188373#M141503 pmonks 2008-09-11T04:28:35Z