Hello Raphael, The simple fix could be :
- 1. Iterating the in memory list of record - 2. For each record, refresh it (re read it from DB to be sure to have the latest version of it) - 3. Then detect inconsistencies (reading the associated denormalization table) Step 2., currently not implemented in [1], could be a way to mitigate these risks. [1] Solving mailbox inconsistencies: https://github.com/linagora/james-project/pull/3110 That way you decrease the concurrency window to the maximum. Cheers, Benoit On 18/02/2020 23:50, Raphaël Ouazana-Sustowski wrote: > Hello, > > Is there a way to solve inconsistencies while not adding new ones? > > When you solve inconsistencies, you have a view of data in memory and > try to fix it. If the data change between the moment you take this view > and the moment you try to fix the inconsistency, you risk to add an > other inconsistency, or worst to cancel a legitimate action. > > Do you see a way to mitigate this risk? > > Regards, > > Raphaël. > > Le 14/02/2020 à 11:06, Đức Trần Tiến a écrit : >> Hello people, >> >> In recent days, James had been recieved a report about the strage >> *MailboxNotFoundException*. There were some investigation to find the >> cause >> of the issue. >> We found that there are some inconsistent between mailbox and >> mailboxPathV2 >> tables. The issue is considered critical and it and bother/annoying users >> to creates, rename, delete mailboxes. >> I had open a PR for demonstrate this problem in unit test >> https://github.com/linagora/james-project/pull/3100. There are some taken >> actions to be resolving the mailbox inconsistencies. >> >> But look back to the bigger picture, there're many tables have close >> relationships, mailbox and mailboxPathV2 is just an example. There are >> several proposals to prevent inconsistent but some have not been >> discussed >> further than an idea: >> >> - Introducing a *transaction* bounded with cassandra (it can >> systematically resolve the issue) >> - Re write the MailboxManager by *EventSourcing* >> - Having tools to fix the already existing inconsistent >> >> *Having tools to fix the already existing inconsistent* >> >> We have: >> - Webadmin Task for solving inconsistent cassandra mappings >> - A self healing MessageFastViewProjections >> >> In developement: >> - Webadmin Task for solving inconsistent mailbox & mailboxPath >> - Retrying on failed mailbox creation/deletion >> >> I want to bring this conversation to the mailling list and hope that >> we can >> contribute solutions, enrich the proposals in order to reduce/fix the >> cassandra inconsistencies. >> >> Thank you! >> >> Tran Tien Duc >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: server-dev-unsubscr...@james.apache.org > For additional commands, e-mail: server-dev-h...@james.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: server-dev-unsubscr...@james.apache.org For additional commands, e-mail: server-dev-h...@james.apache.org
