Backup files on Cache Shutdown

Question

Hi, I am using Partitioned Cache for my cluster of 8 nodes. One of my requirements is write the cache to a file on shutdown and on startup load the cache from that file. So, if all the cache server nodes are shutdown and brought back up again, I want the cache to have the same state as it was before shutdown
     My configuration is as below
     <?xml version="1.0" encoding="UTF-8"?>
     <!DOCTYPE cache-config SYSTEM "cache-config.dtd">
     <cache-config>
     <caching-scheme-mapping>
     <cache-mapping>
     <cache-name>RED</cache-name>
     <scheme-name>ID_Distributed_LocalOverFlow</scheme-name>
     </cache-mapping>
     </caching-scheme-mapping>
     <caching-schemes>
     <distributed-scheme>
     <scheme-name>ID_Distributed_LocalOverFlow</scheme-name>
     <service-name>DistributedCache</service-name>
     <backing-map-scheme>
     <overflow-scheme>
     <scheme-ref>SampleOverflowScheme</scheme-ref>
     </overflow-scheme>
     </backing-map-scheme>
     <backup-storage>
     <type>scheme</type>
     <scheme-name>SampleDiskPersistentScheme</scheme-name>
     </backup-storage>
     <invocation-scheme>
     <scheme-name>example-Invocation</scheme-name>
     <service-name>InvocationService</service-name>
     <autostart>true</autostart>
     </invocation-scheme>
     <autostart>true</autostart>
     </distributed-scheme>
     <overflow-scheme>
     <scheme-name>SampleOverflowScheme</scheme-name>
     <front-scheme>
     <local-scheme>
     <eviction-policy>LRU</eviction-policy>
     <high-units>10</high-units>
     </local-scheme>
     </front-scheme>
     <back-scheme>
     <external-scheme>
     <lh-file-manager/>
     </external-scheme>
     </back-scheme>
     </overflow-scheme>
     <external-scheme>
     <scheme-name>SampleDiskPersistentScheme</scheme-name>
     <lh-file-manager>
     <directory>/home/crddev/logs/crd</directory>
     <file-name>{cache-name}.store</file-name>
     </lh-file-manager>
     </external-scheme>
     <invocation-scheme>
     <scheme-name>example2-Invocation</scheme-name>
     <service-name>InvocationService</service-name>
     <autostart>true</autostart>
     </invocation-scheme>
     </caching-schemes>
     </cache-config>
     I observed that the *.store.* files are being written to but on startup, the cache does not load the entries from that file. Can you please help?
     Thanks,
     Ravi
     Also, is there a way to know the location of the temporary file that the cache is being written to if you do not explicitly specify the file name in <lh-file-manager> (as I did in the SampleOverflowScheme scheme above)?
     Message was edited by: ravikora
     Message was edited by: ravikora

Answer 1

Thanks for your response. I will look into CacheStore for fulfilling our backup needs.
     I have other questions on Local Overflow cache config. Appreciate if you can answer them.As you can see from my configuration file, I have my backing-map defined by an overflow scheme which writes to a local file after inital 10(will be increased in prod context) entries as defined below
     <backing-map-scheme>
     <overflow-scheme>
     <scheme-ref>SampleOverflowScheme</scheme-ref>
     </overflow-scheme>
     </backing-map-scheme>
     <overflow-scheme>
     <scheme-name>SampleOverflowScheme</scheme-name>
     <front-scheme>
     <local-scheme>
     <eviction-policy>LRU</eviction-policy>
     <high-units>10</high-units>
     </local-scheme>
     </front-scheme>
     <back-scheme>
     <external-scheme>
     <lh-file-manager/>
     </external-scheme>
     </back-scheme>
     </overflow-scheme>
     Can you please clarify the below questions about my local overflow cache configuration
     - Is it advisable to have an Overflow scheme (written to the same NFS file by all nodes) for a Distributed Cache setup? Our admin says that one of the applications had a problem with file handlers when they did this and are advising against it. Are there any known problems doing it and can you please advise what overflow scheme works well with partitioned/Distributed Cache.
     -As you can see above, I did not specify the the local file in <lh-file-manager/> . In that case, can you let us know which file that it will overflow to? Also, is it advisable to specify the filename in configuration or should I leave it as above?
     Thanks,
     Ravi