Hi, Nikolay! The user will be able to take the getLastArchivedSegmentIndex every day and remember it and do it, say, for several days.
For example, when starting the application, the getLastArchivedSegmentIndex is 0, then at the end of the first day the value will be 30 at the end of the second 55 and at the end of the third 99. It turns out that 30 segments were used for the first day, 25 for the second and 44 for the third. We take the maximum 44 and multiply it by a DataStorageConfiguration#getWalSegmentSize, and we get the possible maximum that the archive overflow was the least likely. If the user uses compression, then it can be subtracted from the result (result * getMaxSizeCompressedArchivedSegment). 13.02.2021, 10:47, "Nikolay Izhikov" <nizhi...@apache.org>: > Hello, Kirill. > >> It is not possible for us to estimate how much space a user will need in >> the archive so as not to overflow it under its load > > It still not clear for me why do we need those metrics. > Can you please, write down specific scenario - how user will use these > metrics to estimate required WAL volume? > >> 12 февр. 2021 г., в 19:35, ткаленко кирилл <tkalkir...@yandex.ru> >> написал(а): >> >> Hi, Nikolay! >> >> It is not possible for us to estimate how much space a user will need in >> the archive so as not to overflow it under its load. And the proposed >> metrics will allow you to make a rough estimate. >> >> 12.02.2021, 17:23, "Nikolay Izhikov" <nizhi...@apache.org>: >>> Hello, Kirill. >>> >>> Can you, please, clarify - What question about WAL user have in mind? >>> And what answers he(or she) gets with these new metrics? >>> >>>> 12 февр. 2021 г., в 14:26, ткаленко кирилл <tkalkir...@yandex.ru> >>>> написал(а): >>>> >>>> Hi everyone! >>>> At the moment, I have not found an opportunity to estimate how many WAL >>>> segments fall into the archive, say per day. >>>> So I created a ticket https://issues.apache.org/jira/browse/IGNITE-14170 >>>> to add a couple of new metrics.
