da557011ec
The handoffs_first mode in the replicator has the useful behavior of processing all handoff parts across all disks until there aren't any handoffs anymore on the node [1] and then it seemingly tries to drop back into normal operation. In practice I've only ever heard of handoffs_first used while rebalancing and turned off as soon as the rebalance finishes - it's not recommended to run with handoffs_first mode turned on and it emits a warning on startup if option is enabled. The handoffs_first mode on the reconstructor doesn't work - it was prioritizing handoffs *per-part* [2] - which is really unfortunate because in the reconstructor during a rebalance it's often *much* more attractive from an efficiency disk/network perspective to revert a partition from a handoff than it is to rebuild an entire partition from another primary using the other EC fragments in the cluster. This change deprecates handoffs_first in favor of handoffs_only in the reconstructor which is far more useful - and just like handoffs_first mode in the replicator - it gives the operator the option of forcing the consistency engine to focus on rebalance. The handoffs_only behavior is somewhat consistent with the replicator's handoffs_first option (any error on any handoff in the replicactor will make it essentially handoff only forever) but the option does what you want and is named correctly in the reconstructor. For consistency with the replicator the reconstructor will mostly honor the handoffs_first option, but if you set handoffs_only in the config it always takes precedence. Having handoffs_first in your config always results in a warning, but if handoff_only is not set and handoffs_first is true the reconstructor will assume you need handoffs_only and behaves as such. When running in handoffs_only mode the reconstructor will start to log a warning every cycle if you leave it running in handoffs_only after it finishes reverting handoffs. However you should be monitoring on-disk partitions and disable the option as soon as the cluster finishes the full rebalance cycle. 1. Ia324728d42c606e2f9e7d29b4ab5fcbff6e47aea fixed replicator handoffs_first "mode" 2. Unlike replication each partition in a EC policy can have a different kind of job per frag_index, but the cardinality of jobs is typically only one (either sync or revert) unless there's been a bunch of errors during write and then handoffs partitions maybe hold a number of different fragments. Known-Issues: handoffs_only is not documented outside of the example config, see lp bug #1626290 Closes-Bug: #1653018 Change-Id: Idde4b6cf92fab6c45f2c0c2733277701eb436898 |
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| .. | ||
| account-server.conf-sample | ||
| container-reconciler.conf-sample | ||
| container-server.conf-sample | ||
| container-sync-realms.conf-sample | ||
| dispersion.conf-sample | ||
| drive-audit.conf-sample | ||
| internal-client.conf-sample | ||
| memcache.conf-sample | ||
| mime.types-sample | ||
| object-expirer.conf-sample | ||
| object-server.conf-sample | ||
| proxy-server.conf-sample | ||
| rsyncd.conf-sample | ||
| swift-rsyslog.conf-sample | ||
| swift.conf-sample | ||