https://docs.datastax.com/en/cassandra/2.0/cassandra/configuration/configLogArchive_t.html
Sean Durity From: Anuj Wadehra [mailto:anujw_2...@yahoo.co.in] Sent: Wednesday, April 27, 2016 10:44 PM To: user@cassandra.apache.org Subject: RE: Inconsistent Reads after Restoring Snapshot No.We are not saving them.I have never read that in DataStax documentation. Thanks Anuj Sent from Yahoo Mail on Android<https://overview.mail.yahoo.com/mobile/?.src=Android> On Thu, 28 Apr, 2016 at 12:45 AM, sean_r_dur...@homedepot.com<mailto:sean_r_dur...@homedepot.com> <sean_r_dur...@homedepot.com<mailto:sean_r_dur...@homedepot.com>> wrote: What about the commitlogs? Are you saving those off anywhere in between the snapshot and the crash? Sean Durity From: Anuj Wadehra [mailto:anujw_2...@yahoo.co.in] Sent: Monday, April 25, 2016 10:26 PM To: User Subject: Inconsistent Reads after Restoring Snapshot Hi, We have 2.0.14. We use RF=3 and read/write at Quorum. Moreover, we dont use incremental backups. As per the documentation at https://docs.datastax.com/en/cassandra/2.0/cassandra/operations/ops_backup_snapshot_restore_t.html , if i need to restore a Snapshot on SINGLE node in a cluster, I would run repair at the end. But while the repair is going on, reads may get inconsistent. Consider following scenario: 10 AM Daily Snapshot taken of node A and moved to backup location 11 AM A record is inserted such that node A and B insert the record but there is a mutation drop on node C. 1 PM Node A crashes and data is restored from latest 10 AM snapshot. Now, only Node B has the record. Now, my question is: Till the repair is completed on node A,a read at Quorum may return inconsistent result based on the nodes from which data is read.If data is read from node A and node C, nothing is returned and if data is read from node A and node B, record is returned. This is a vital point which is not highlighted anywhere. Please confirm my understanding.If my understanding is right, how to make sure that my reads are not inconsistent while a node is being repair after restoring a snapshot. I think, autobootstrapping the node without joining the ring till the repair is completed, is an alternative option. But snapshots save lot of streaming as compared to bootstrap. Will incremental backups guarantee that Thanks Anuj Sent from Yahoo Mail on Android<https://overview.mail.yahoo.com/mobile/?.src=Android> ________________________________ The information in this Internet Email is confidential and may be legally privileged. It is intended solely for the addressee. Access to this Email by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful. When addressed to our clients any opinions or advice contained in this Email are subject to the terms and conditions expressed in any applicable governing The Home Depot terms of business or client engagement letter. The Home Depot disclaims all responsibility and liability for the accuracy and content of this attachment and for any damages or losses arising from any inaccuracies, errors, viruses, e.g., worms, trojan horses, etc., or other items of a destructive nature, which may be contained in this attachment and shall not be liable for direct, indirect, consequential or special damages in connection with this e-mail message or its attachment. ________________________________ The information in this Internet Email is confidential and may be legally privileged. It is intended solely for the addressee. Access to this Email by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful. When addressed to our clients any opinions or advice contained in this Email are subject to the terms and conditions expressed in any applicable governing The Home Depot terms of business or client engagement letter. The Home Depot disclaims all responsibility and liability for the accuracy and content of this attachment and for any damages or losses arising from any inaccuracies, errors, viruses, e.g., worms, trojan horses, etc., or other items of a destructive nature, which may be contained in this attachment and shall not be liable for direct, indirect, consequential or special damages in connection with this e-mail message or its attachment.
