This obscure feature of Cassandra is called "haunted handoff". Happy (early) April Fools :)
From: aaron morton [mailto:aa...@thelastpickle.com] Sent: Monday, March 18, 2013 7:45 PM To: user@cassandra.apache.org Subject: Re: Lots of Deleted Rows Came back after upgrade 1.1.6 to 1.1.10 As you see, this node thinks lots of ranges are out of sync which shouldn't be the case as successful repairs where done every night prior to the upgrade. Could this be explained by writes occurring during the upgrade process ? I found this bug which touches timestamp and tomstones which was fixed in 1.1.10 but am not 100% sure if it could be related to this issue: https://issues.apache.org/jira/browse/CASSANDRA-5153 Me neither, but the issue was fixed in 1.1.0 It appears that the repair task that I executed after upgrade, brought back lots of deleted rows into life. Was it entire rows or columns in a row? Do you know if row level or column level deletes were used ? Can you look at the data in cassanca-cli and confirm the timestamps on the columns make sense ? Cheers ----------------- Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 16/03/2013, at 2:31 PM, Arya Goudarzi <gouda...@gmail.com<mailto:gouda...@gmail.com>> wrote: Hi, I have upgraded our test cluster from 1.1.6 to 1.1.10. Followed by running repairs. It appears that the repair task that I executed after upgrade, brought back lots of deleted rows into life. Here are some logistics: - The upgraded cluster started from 1.1.1 -> 1.1.2 -> 1.1.5 -> 1.1.6 - Old cluster: 4 node, C* 1.1.6 with RF3 using NetworkTopology; - Upgrade to : 1.1.10 with all other settings the same; - Successful repairs were being done on this cluster every night; - Our clients use nanosecond precision timestamp for cassandra calls; - After upgrade, while running repair I say some log messages like this in one node: system.log.5: INFO [AntiEntropyStage:1] 2013-03-15 19:55:54,847 AntiEntropyService.java (line 1022) [repair #0990f320-8da9-11e2-0000-e9b2bd8ea1bd] Endpoints /XX.194.60 and /23.20.207.56<http://23.20.207.56/> have 2223 range(s) out of sync for App system.log.5: INFO [AntiEntropyStage:1] 2013-03-15 19:55:54,877 AntiEntropyService.java (line 1022) [repair #0990f320-8da9-11e2-0000-e9b2bd8ea1bd] Endpoints /XX.250.43 and /23.20.207.56<http://23.20.207.56/> have 161 range(s) out of sync for App system.log.5: INFO [AntiEntropyStage:1] 2013-03-15 19:55:55,097 AntiEntropyService.java (line 1022) [repair #0990f320-8da9-11e2-0000-e9b2bd8ea1bd] Endpoints /XX.194.60 and /23.20.250.43<http://23.20.250.43/> have 2294 range(s) out of sync for App system.log.5: INFO [AntiEntropyStage:1] 2013-03-15 19:55:59,190 AntiEntropyService.java (line 789) [repair #0990f320-8da9-11e2-0000-e9b2bd8ea1bd] App is fully synced (13 remaining column family to sync for this session) As you see, this node thinks lots of ranges are out of sync which shouldn't be the case as successful repairs where done every night prior to the upgrade. The App CF uses SizeTiered with gc_grace of 10 days. It has caching = 'ALL', and it is fairly small (11Mb on each node). I found this bug which touches timestamp and tomstones which was fixed in 1.1.10 but am not 100% sure if it could be related to this issue: https://issues.apache.org/jira/browse/CASSANDRA-5153 Any advice on how to dig deeper into this would be appreciated. Thanks, -Arya _______________________________________________ This message may contain information that is confidential or privileged. If you are not an intended recipient of this message, please delete it and any attachments, and notify the sender that you have received it in error. Unless specifically stated in the message or otherwise indicated, you may not uplicate, redistribute or forward this message or any portion thereof, including any attachments, by any means to any other person, including any retail investor or customer. This message is not a recommendation, advice, offer or solicitation, to buy/sell any product or service, and is not an official confirmation of any transaction. Any opinions presented are solely those of the author and do not necessarily represent those of Barclays. This message is subject to terms available at: www.barclays.com/emaildisclaimer and, if received from Barclays' Sales or Trading desk, the terms available at: www.barclays.com/salesandtradingdisclaimer/. By messaging with Barclays you consent to the foregoing. Barclays Bank PLC is a company registered in England (number 1026167) with its registered office at 1 Churchill Place, London, E14 5HP. This email may relate to or be sent from other members of the Barclays group. _______________________________________________
