Given the hardy reviews and timing, we recently shifted from 90.3 (apache) to 90.4rc2 (the July 24th one that Stack posted -- 0.90.4, r1150278).
We had a network switch go down last night which caused an apparent network partition between two of our region servers and one or more zk nodes. (We're still piecing together the situation). Anyway, things *seemed* to recover fine. However, this morning we realized that we lost some data that was generated just before the problems occurred. It looks like h002 went down nearly immediately at around 8pm while h001 didn't go down until around 8:10pm (somewhat confused by this). We're thinking that this may have contributed to the problem. The particular table that had data issues is a very small table with a single region that was running on h002 when it went down. We know the corruption/lack of edits affected two tables. It extended across a number of rows and actually appears to reach back up to data inserted 6 hours earlier (estimate). The two tables we can verify errors on are each probably at most 10-20k <1k rows. Some places rows that were added are completely missing and some just had missing cell edits. As an aside, I was thinking there was a time based memstore flush in addition to a size one. But upon reviewing the hbase default configuration, I don't see mention of it. Is this purely size based? We don't have the tools in place to verify exactly what other data or tables may have been impacted. The log files are at the paste bin links below. The whole cluster is 8 nodes + master, 3 zk nodes running on separate machines. We run with mostly standard settings but do have the following settings: heap: 12gb regionsize 4gb, (due to lots of cold data and not enough servers, avg 300 regions/server) mslab: 4m/512k (due to somewhat frequent updates to larger objects in the 200-500k size range) We've been using hbase for about a year now and have been nothing but happy with it. The failure state that we had last night (where only some region servers cannot talk to some zk servers) seems like a strange one. Any thoughts? (beyond chiding for switching to a rc) Any opinions whether we should we roll back to 90.3 (or 90.3+cloudera)? Thanks for any help, Jacques master: http://pastebin.com/aG8fm2KZ h001: http://pastebin.com/nLLk06EC h002: http://pastebin.com/0wPFuZDx h003: http://pastebin.com/3ZMV01mA h004: http://pastebin.com/0YVefuqS h005: http://pastebin.com/N90LDjvs h006: http://pastebin.com/gM8umekW h007: http://pastebin.com/0TVvX68d h008: http://pastebin.com/mV968Cem
