Hello, Nikolay! Online rebuild causes unpredictable behaviour of the indexed SQL queries. For example, if a query plan requires an index scan, we will instead resort to the full scan which is unacceptable for some users. So sometimes it’s better to shutdown the node than mess up the application.
Kind regards, Semyon. > Hello, Семен. > > Why index rebuild should be done in maintenance mode? > >> 31 мая 2022 г., в 18:24, Данилов Семён <samvi...@yandex.ru> написал(а): >> >> Hello, igniters! >> >> I want to propose a new control.sh cache sub-command that schedules a >> rebuild of cache indexes in the maintenance mode. >> We already have a force rebuild command but sometimes (for example, under >> load) user may want to first stop the node and then rebuild indexes. >> For this scenario we can add a command that creates a maintenance task and >> then after restart node will enter the maintenance mode and rebuild >> specified indexes. >> >> I propose the following API: >> --cache schedule_indexes_rebuild --node-id nodeId --target >> cacheName1=index1,...indexN >> Schedules rebuild of the indexes for specified caches via the Maintenance >> Mode. >> >> Parameters: >> --node-id - (Optional) Specify node for indexes rebuild. >> --target - Cache name with optionally specified indexes. If indexes are not >> specified then all indexes of the cache will be scheduled for the rebuild >> operation. >> >> As you can see, the user can provide a node id to schedule the rebuild on a >> specific node (otherwise the rebuild will be scheduled for all of the nodes) >> and targets (specific indexes of a cache or all of the indexes of a cache). >> There is a ticket[1] and a pull request[2] for my proposal. >> >> WDYT? >> >> Kind regards, >> Semyon. >> >> [1] https://issues.apache.org/jira/browse/IGNITE-17002 >> [2] https://github.com/apache/ignite/pull/10042
