{"action":"opened","issue":{"url":"https://api.github.com/repos/arangodb/arangodb/issues/7650","repository_url":"https://api.github.com/repos/arangodb/arangodb","labels_url":"https://api.github.com/repos/arangodb/arangodb/issues/7650/labels{/name}","comments_url":"https://api.github.com/repos/arangodb/arangodb/issues/7650/comments","events_url":"https://api.github.com/repos/arangodb/arangodb/issues/7650/events","html_url":"https://github.com/arangodb/arangodb/issues/7650","id":387696208,"node_id":"MDU6SXNzdWUzODc2OTYyMDg=","number":7650,"title":"Does arangodump lock collections ? Is it related to replication ?","user":{"login":"matcho","id":2674752,"node_id":"MDQ6VXNlcjI2NzQ3NTI=","avatar_url":"https://avatars3.githubusercontent.com/u/2674752?v=4","gravatar_id":"","url":"https://api.github.com/users/matcho","html_url":"https://github.com/matcho","followers_url":"https://api.github.com/users/matcho/followers","following_url":"https://api.github.com/users/matcho/following{/other_user}","gists_url":"https://api.github.com/users/matcho/gists{/gist_id}","starred_url":"https://api.github.com/users/matcho/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/matcho/subscriptions","organizations_url":"https://api.github.com/users/matcho/orgs","repos_url":"https://api.github.com/users/matcho/repos","events_url":"https://api.github.com/users/matcho/events{/privacy}","received_events_url":"https://api.github.com/users/matcho/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":0,"created_at":"2018-12-05T10:43:08Z","updated_at":"2018-12-05T10:43:08Z","closed_at":null,"author_association":"NONE","body":"## My Environment\r\n\r\n* __ArangoDB Version__:        3.3.19\r\n* __Storage Engine__:             RocksDB\r\n* __Deployment Mode__:       Master/Slave\r\n* __Infrastructure__:               own\r\n* __Operating System__:        Debian 9 / Ubuntu 18.04\r\n* __Used Package__:              Debian or Ubuntu .deb\r\n\r\n## Component, Query & Data\r\n\r\n__Affected feature__:\r\narangodump\r\n\r\n\r\n## Steps to reproduce\r\n\r\n1. have a database with many collections and millions of docs on a master server, replicated on a slave\r\n2. regularly read and write into those collections (~10 writes/s, lots of reads)\r\n3. use `arangodump` on the master to backup this database\r\n4. see locks appear\r\n5. stop replication from slave (`arangodump` is still running)\r\n6. see locks disappear\r\n\r\n__Problem__:\r\n20 minutes (in our case) after executing `arangodump`, locks appear on the database. We detect those locks because read operations on different collections fail: they get stuck and eventually timeout with a lock error (I don't have the exact error message at hand right now).\r\n\r\nSomeone said in #1070 :\r\n> According to the docs, arangodump locks the (entire?) database during the export, as long as a single instance of the server is used. \r\n\r\nIs it true ? I cannot find a mention of such locking in the current docs…\r\n\r\nIn parallel of `arangodump`, we have a replication running, that has to deal with huge lots of documents writes during the night, and kind of stalls periodically, as mentioned in #7410 .\r\n\r\nWe added the daily `arangodump` (at 10 AM) recently, and the lock issue had never occurred before.\r\n\r\nAfter stopping the replication, even though `arangodump` is still running, the locks seem to disappear (timeout ?) after a few minutes (15 ? 30 ? didn't count…) and the database is available again for regular read and write operations.\r\n\r\n__Expected result__:\r\nIt would be great to be able to run replication(s) and dump at the same time, and still use the database.\r\n\r\nThanks a lot\r\nMathias\r\n"}}
{"actor":{"display_login":"matcho"}}