Hi Michael, Does this behavior (of queries using the old indexes while reindexing is going on) apply :
1. to manually invoked reindexing - not just to reindexing caused by an ML upgrade ? 2. whether or not "index detection" is set to "automatic" or "none" ? Regards, Danny ---------- Forwarded message ---------- From: Michael Blakeley <[email protected]> Date: Tue, May 14, 2013 at 4:19 PM Subject: Re: [MarkLogic Dev General] Reindexing estimation To: MarkLogic Developer Discussion <[email protected]> The database is designed so that indexes are versioned and forward-compatible. Thus reindexing is a fully online operation. After a major upgrade the old indexes are still there. The forests want to build new ones, hence the reindex. But until that happens, queries use whatever is available. This passage from http://docs.marklogic.com/admin-help/database might help: > • format compatibility specifies the version compatibility that MarkLogic Server applies to the indexes for this database during request evaluation. Setting this to a value other than automatic specifies that all forest data has the specified on-disk format, and it disables the automatic checking for index compatibility information. The automatic detection occurs during database startup and after any database configuration changes, and can take some time and system resources for very large forests and for very large clusters. The default value of automatic is recommended for most installations. > • index detection specifies whether to auto-detect index compatibility between the content and the current database settings. This detection occurs during database startup and after any database configuration changes, and can take some time and system resources for very large forests and for very large clusters. Setting this to none also causes queries to use the current database index settings, even if some settings have not completed reindexing. The default value of automatic is recommended for most installations. -- Mike On 14 May 2013, at 09:20 , Danny Sinang <[email protected]> wrote: > HI Michael, > > What do you mean by "Queries will use backward-compatibility mode" ? > > During reindexing, queries would be slower since there isn't any completed index yet, right ? > > Also, while reindexing has not completed, will there be any facets available ? > > Regards, > Danny > > > On Tue, May 14, 2013 at 11:56 AM, Michael Blakeley <[email protected]> wrote: > Probably not, because disk speed is often the bottleneck at that scale and you haven't said anything about that. But it will take roughly as long as ingesting all the data would take. My guess is that could be anywhere from 1-10 days. > > If you find that reindexing is bad for query performance, you can disable it until you are ready. Queries will use backward-compatibility mode, just like they would during reindexing anyway. Then you can run reindexing a little at a time, say on the weekends, until you have caught up. That will take longer, but may impact operations less. > > -- Mike > > On May 14, 2013, at 6:04, "Roy Chowdhury, Soumadri" < [email protected]> wrote: > >> Hi, >> >> I am upgrading from MarkLogic 5.x to 6, which contains ~2 terabytes data. I believe while upgrading, MarkLogic will reindex all the data. The database has ~17 range indexes defined. Can anyone help me how to estimate approximately the time MarkLogic will take to reindex all the data, without actually starting it and checking the estimation from 'Status' tab of database? >> >> Regards, >> Soumadri Roy >> >> >> "This e-mail and any attachments transmitted with it are for the sole use of the intended recipient(s) and may contain confidential , proprietary or privileged information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. Any unauthorized review, use, disclosure, dissemination, forwarding, printing or copying of this e-mail or any action taken in reliance on this e-mail is strictly prohibited and may be unlawful." >> _______________________________________________ >> General mailing list >> [email protected] >> http://developer.marklogic.com/mailman/listinfo/general > > _______________________________________________ > General mailing list > [email protected] > http://developer.marklogic.com/mailman/listinfo/general > > > _______________________________________________ > General mailing list > [email protected] > http://developer.marklogic.com/mailman/listinfo/general _______________________________________________ General mailing list [email protected] http://developer.marklogic.com/mailman/listinfo/general
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