Replicated Cache - Failover & Failback
abcdefg1234 Jan 23, 2009 11:06 AMWe have a 2 node replicated cache i.e.
node1 --> application instance 1 --> cache instance 1
node2 --> application instance 2 --> cache instance 2
According to the configuration below, everything seems to work fine. i.e when node 1 is shutdown and brought back up, any changes made to cache instance 2 are replicated.
Problem: - However, what if the application server node is still running, but only the cache instance on node 1 has to be shutdown or crashes. I would think that the application on node 1 can access to the cache on node 2. That does'nt happen though. Is it possible to have a configuration wherein, all the instances in the clustered cache are searched for.
I even tried the ClusteredCacheLoader as shown in the configuration below, but that does not make a difference. Isi'nt that what ClusteredCacheLoader is used for??
-------------------------------------------------------------------------------- <?xml version="1.0" encoding="UTF-8"?> <!-- ===================================================================== --> <!-- --> <!-- Sample TreeCache Service Configuration --> <!-- --> <!-- ===================================================================== --> <server> <classpath codebase="./lib" archives="jbosscache-core.jar, jboss-common-core.jar, jgroups.jar"/> <!-- ==================================================================== --> <!-- Defines TreeCache configuration --> <!-- ==================================================================== --> <mbean code="org.jboss.cache.TreeCache" name="jboss.cache:service=TreeCache"> <depends>jboss:service=Naming</depends> <depends>jboss:service=TransactionManager</depends> <!-- Configure the TransactionManager --> <attribute name="TransactionManagerLookupClass">org.jboss.cache.transaction.DummyTransactionManagerLookup </attribute> <!-- Node locking level : SERIALIZABLE REPEATABLE_READ (default) READ_COMMITTED READ_UNCOMMITTED NONE --> <attribute name="IsolationLevel">REPEATABLE_READ</attribute> <!-- Valid modes are LOCAL, REPL_ASYNC and REPL_SYNC --> <attribute name="CacheMode">REPL_SYNC</attribute> <!-- Just used for async repl: use a replication queue --> <attribute name="UseReplQueue">false</attribute> <!-- Replication interval for replication queue (in ms) --> <attribute name="ReplQueueInterval">0</attribute> <!-- Max number of elements which trigger replication --> <attribute name="ReplQueueMaxElements">0</attribute> <!-- Name of cluster. Needs to be the same for all TreeCache nodes in a cluster in order to find each other. --> <attribute name="ClusterName">JBossCache-Cluster</attribute> <attribute name="ClusterConfig"> <config> <!-- UDP: if you have a multihomed machine, set the bind_addr attribute to the appropriate NIC IP address, e.g bind_addr="192.168.0.2". The mcast_addr and mcast_port should be different from the cluster address and port to avoid contention. --> <!-- UDP: On Windows machines, because of the media sense feature being broken with multicast (even after disabling media sense) set the loopback attribute to true --> <UDP mcast_addr="224.10.10.10" mcast_port="45566" ip_ttl="64" ip_mcast="true" mcast_send_buf_size="150000" mcast_recv_buf_size="80000" ucast_send_buf_size="150000" ucast_recv_buf_size="80000" loopback="false" bind_addr="127.0.0.1" bind_port="5544" /> <PING timeout="2000" num_initial_members="3" up_thread="false" down_thread="false"/> <MERGE2 min_interval="10000" max_interval="20000"/> <!-- <FD shun="true" up_thread="true" down_thread="true" />--> <FD_SOCK/> <VERIFY_SUSPECT timeout="1500" up_thread="false" down_thread="false"/> <pbcast.NAKACK gc_lag="50" retransmit_timeout="600,1200,2400,4800" max_xmit_size="8192" up_thread="false" down_thread="false"/> <UNICAST timeout="600,1200,2400" window_size="100" min_threshold="10" down_thread="false"/> <pbcast.STABLE desired_avg_gossip="20000" up_thread="false" down_thread="false"/> <FRAG frag_size="8192" down_thread="false" up_thread="false"/> <pbcast.GMS join_timeout="5000" join_retry_timeout="2000" shun="true" print_local_addr="true"/> <pbcast.STATE_TRANSFER up_thread="true" down_thread="true"/> </config> </attribute> <!-- Whether or not to fetch state on joining a cluster --> <attribute name="FetchStateOnStartup">true</attribute> <!-- The max amount of time (in milliseconds) we wait until the initial state (ie. the contents of the cache) are retrieved from existing members in a clustered environment --> <attribute name="InitialStateRetrievalTimeout">5000</attribute> <!-- The max amount of time (in milliseconds) we wait until the state (ie. the contents of the cache) are retrieved from existing members in a clustered environment --> <attribute name="StateRetrievalTimeout">20000</attribute> <!-- Number of milliseconds to wait until all responses for a synchronous call have been received. --> <attribute name="SyncReplTimeout">20000</attribute> <!-- Max number of milliseconds to wait for a lock acquisition --> <attribute name="CacheLoaderConfig" replace="false"> <config> <cacheloader> <class>org.jboss.cache.loader.ClusteredCacheLoader</class> <properties> timeout=15000 </properties> </cacheloader> </config> </attribute> </mbean> </server> ------------------------------------------------------------------------------------