The thing is that this is a disk level operation. It pretty much rsyncs the files from the current master shard to the node when it comes back online. This would be OK if the replica shards matched the master but that is only normally the case if the shard was moved to the node after it was mostly complete and then you've had only a few writes. Normally shards don't match each other because the way the index is maintained is nondeterministic.
The translog replay is only used as a catch up after the rsync-like step. This is something that is being worked on. Its certainly my biggest complaint about elasticsearch but I'm confident that it'll get better. Nik On Nov 20, 2014 11:11 PM, "Mark Walkom" <markwal...@gmail.com> wrote: > It will enter recovery where it syncs at the segment level from the > current primary, then the translog gets shipped over and (re)played, which > brings it all up to date. > > On 21 November 2014 14:51, Yves Dorfsman <y...@zioup.com> wrote: > >> >> If you do disable allocation before you reboot a node and a client writes >> to a shard that had a replica on that node, does the entire replica gets >> copied when the node come up? Or does it get just updated? >> >> On Thursday, 20 November 2014 19:52:26 UTC-7, Mark Walkom wrote: >>> >>> You should disable allocation before you reboot, that will save a lot of >>> shard shuffling - http://www.elasticsearch.org/guide/en/elasticsearch/ >>> reference/current/setup-upgrade.html#rolling-upgrades >>> >>> On 21 November 2014 13:48, Konstantin Erman <kon...@gmail.com> wrote: >>> >>>> I work on an experimental cluster of ES nodes running on Windows Server >>>> machines. Once in a while we have a need to reboot machines. The initial >>>> state - cluster is green and well balanced. One machine is gracefully taken >>>> offline and then after necessary service is performed it comes back online. >>>> All the hardware and file system content is intact. As soon as ES service >>>> starts on that machine, it assumes that there is no usable data locally and >>>> recovers as much data as it deems necessary for balancing from other nodes. >>>> >>>> This behavior puzzles me, because most of the data shards stored on >>>> that machine file system can be reused as they are. Cluster stores logs, so >>>> all indices except those for the current day never ever change until they >>>> get deleted. Can't ES node detect that it has perfect copies of some >>>> (actually most) of the shards and instead of copying them over just mark >>>> them as up to date? >>>> >>>> I suspect I don't know about some step to enable this behavior and I'm >>>> looking to enable it. Any advice? >>>> >>>> Thank you! >>>> Konstantin >>>> >>>> -- >> You received this message because you are subscribed to the Google Groups >> "elasticsearch" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to elasticsearch+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/elasticsearch/51b3ff69-a126-4f2f-9838-0098bc26694d%40googlegroups.com >> <https://groups.google.com/d/msgid/elasticsearch/51b3ff69-a126-4f2f-9838-0098bc26694d%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to elasticsearch+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elasticsearch/CAF3ZnZmxZuSjJAJPj_yKT6d8_L-Mx6ceZfDNmJCLkSOXsfeydQ%40mail.gmail.com > <https://groups.google.com/d/msgid/elasticsearch/CAF3ZnZmxZuSjJAJPj_yKT6d8_L-Mx6ceZfDNmJCLkSOXsfeydQ%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to elasticsearch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/CAPmjWd09LRJk89wdHybYy48FMpCaYa1wTJ9HX9uX%2BjvNjvYq2g%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
