https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=18966
--- Comment #1 from Jonathan Druart <jonathan.dru...@bugs.koha-community.org> --- Created attachment 65151 --> https://bugs.koha-community.org/bugzilla3/attachment.cgi?id=65151&action=edit Bug 18966: Do not deal with duplicate issue_id on checkin Koha suffers of big bugs due to its history: When data are deleted, they are moved to another tables. For instance issues and old_issues: when a checkin is done, it is moved to the old_issues table. That leads to a main problem that is described on https://wiki.koha-community.org/wiki/DBMS_auto_increment_fix However we tried first to fix the problem (for issues/old_issues) at code level on bug 18242. The goal was to prevent data lost. Data lost may happens in this case: Check an item out (issue_id = 1) Check an item in (issue_id = 1) Restart MySQL (reset auto increment for issue_id to 1) Check an item out (issue_id = 1) Check an item in => BOOM, the issue_id is a PK in old_issues and the move fails. Before bug 18242 the data were lost, we inserted the value into old_issues, which fails silently (because of RaiseError set to 0 in Koha::Database), then delete the row from issues. That has been fixed using a transaction. This patch introduced a regression we tried to fix on bug 18651 comment 0, the patron was charged even if the checkin was rejected. A good way to fix that would have been to LOCK the tables: 1- Start a transaction 2- LOCK the table to make sure nobody will read id and avoid race conditions 3- Move the content from one table to the other, dealing with ids 4- UNLOCK the table 5- Commit the transaction But there were problems using LOCK and DBIx::Class (See commit 905572910b3a - Do no LOCK/UNLOCK the table). Finally the solution implemented is not acceptable for several reasons: - batch checkins may fail - issue_id will always stay out of sync (between issues and old_issues) See 18651 comment 66. Since the next stable releases are very soon, and we absolutely need to fix this problem, I am suggesting to: 1- Execute the move in a transaction to avoid data lost and reject the checkin if we face IDs dup => It will only reject 1 checkin (max is 1 * MySQL restart), no need to deal with race conditions, 2- Display a warning on the checkin page and link to a solution/explanation 3- Communicate as much as we can on the proper fix: Update auto increment values when the DBMS is restarted - https://wiki.koha-community.org/wiki/DBMS_auto_increment_fix 4- Display a warning on the about page for corrupted data (see bug 18931) 5- Write and make available a maintenance script to fix corrupted data (TODO LATER) -- You are receiving this mail because: You are watching all bug changes. _______________________________________________ Koha-bugs mailing list Koha-bugs@lists.koha-community.org http://lists.koha-community.org/cgi-bin/mailman/listinfo/koha-bugs website : http://www.koha-community.org/ git : http://git.koha-community.org/ bugs : http://bugs.koha-community.org/