Q & A On Elastic Search With Classic Message Store
(Doc ID 2416387.1)
Last updated on MAY 05, 2021
Applies to:Oracle Communications Messaging Server - Version 8.0.2 and later
Information in this document applies to any platform.
Information pertaining to the Elasticsearch options in the documentation for Messaging Server and the various items linked from there and the Searchengine Option, which is identified as a restricted option.
To view full details, sign in with your My Oracle Support account.
Don't have a My Oracle Support account? Click to get started!
In this Document
|Questions and Answers|
|1. Are there more details on the restricted Searchengine option?|
|3. Are there specific details on how the classic store acts as a "client" for Elastic search, in terms of how records are inserted and queried for?|
|4. Are there other items that are appropriate to provide for a successful test deployment?|
|5. Are there any specific Java requirements for ISC on the backends for using Elastic Search?|
|6. Is there a summary of the isc_client options?|
talks about installing ISC on the "message access tier host(s)" and LMTP.
It also says, "Messages that arrive in the store through the IMAP APPEND command or the imsrestore command are to be processed by ISC on the message access tier host(s)."
Does this mean that we cannot use Elastic if we are not using LMTP ?
Can we not run ISC on the backends with ims_master?
|8. Does "message access tier" mean "backends" rather than "frontends"?|
|10. How to initiate a full reindex? Or partial reindex, for that matter?|
|The documentation about numshards https://docs.oracle.com/communications/F15020_01/doc.803/f15150.pdf#page=313&zoom=auto,-208,692 says "The number of shards cannot be changed after the index is created."|
|So if something like that needs to be changed or if storesource option is disabled and needed to to be rebuilt... How would one go about rebuilding?|
|What would need to be done to start over?|
From the Elastic Search server side, this easy enough: destroy/reinstall the the Elastic Search server.
But on the Messaging Server side, how to tell it to resend everything to Elastic?
|How to decide on the number of shards?|
|If a 3-node cluster of Elastic Search servers exists, should all three names be specified in the hostlist parameter?|
How does Messaging Server decide which one to use? Or, does it only use one?
|Is information about the number of shards (or which shard a folder is in), stored in store.idx or somewhere on the Messaging Server side? |
|11. Where is the Indexed Search Converter (ISC) going to store 30 days worth of incoming message data?|
|Where does data live?|
Is there an option to specify the directory/path?
|12. How can one measure the effectiveness of this cache so one can make informed tuning decisions?|
|> ... ISC will have to re-convert any new document with the same content ...|
|In the above statement, "document" means email message, correct?|
|What about moving messages from one folder to another? Does that involve this?|
|13. Part of the answer for question 6:|
|Does that actually check with the Elastic Search service to see if the folder is indexed?|
|14. Perhaps walking through the scenarios and provide examples of relevant parts of the output would be helpful.|
|The "imcheck -m" command is a normal command which has existed for a long time.|
Does it now also cause some action related to Elastic Search? Exactly when/what/how?
|In the 5th line of the output:|
|The above is the same on the system where the new test facility (refer to: Doc ID 2630186.1) is being performed and on a system that has had nothing to do with Elastic.|
|Is that the "Folder Flags" that's being talked about?|
|And once that folder has been indexed with Elastic, that flag will be set to "I"?|
|So in the first part of the answer:|
|> 1) Mails sent when ES is down won't get indexed in ES.|
|Running imcheck -m on a folder will do what, exactly? And are you saying that if Elastic is ever down, that will need to be performed on every folder?|
|> 2) Re-indexing of messages is possible when Elasticsearch host is changed, or in the case the indexes of all the emails of a mailbox are to be rebuilt.|
|Yes, is the point of this question.|
If the Elastic service needs to be reinitialized, how does one cause folders, which had already been indexed on the previous service, to be indexed on the new service?
|It sounds like the answer is to run "imcheck -m" on every folder.|
|* That sounds like it would be difficult because "imcheck -m" does not take wildcards. One would need to list every folder and then run "imcheck -m" on each folder.|
|How would "imcheck -m" cause the folder index to be rebuilt? What does it check? What does it do? How could one monitor its progress?|