Xena Series Release Notes

2.28.0

New Features

  • swift-manage-shard-ranges improvements:

    • Exit codes are now applied more consistently:

      • 0 for success

      • 1 for an unexpected outcome

      • 2 for invalid options

      • 3 for user exit

      As a result, some errors that previously resulted in exit code 2 will now exit with code 1.

    • Added a new ‘repair’ command to automatically identify and optionally resolve overlapping shard ranges.

    • Added a new ‘analyze’ command to automatically identify overlapping shard ranges and recommend a resolution based on a JSON listing of shard ranges such as produced by the ‘show’ command.

    • Added a --includes option for the ‘show’ command to only output shard ranges that may include a given object name.

    • Added a --dry-run option for the ‘compact’ command.

    • The ‘compact’ command now outputs the total number of compactible sequences.

  • Partition power increase improvements:

    • The relinker now spawns multiple subprocesses to process disks in parallel. By default, one worker is spawned per disk; use the new --workers option to control how many subprocesses are used. Use --workers=0 to maintain the previous behavior.

    • The relinker can now target specific storage policies or partitions by using the new --policy and --partition options.

  • More daemons now support systemd notify sockets.

  • The container-reconciler now scales out better with new processes, process, and concurrency options, similar to the object-expirer.

Deprecation Notes

  • Container sharding deprecations:

    • Added a new config option, shrink_threshold, to specify the absolute size below which a shard will be considered for shrinking. This overrides the shard_shrink_point configuration option, which expressed this as a percentage of shard_container_threshold. shard_shrink_point is now deprecated.

    • Similar to above, expansion_limit was added as an absolute-size replacement for the now-deprecated shard_shrink_merge_point configuration option.

Bug Fixes

  • Sharding improvements:

    • When building a listing from shards, any failure to retrieve listings will result in a 503 response. Previously, failures fetching a partiucular shard would result in a gap in listings.

    • Container-server logs now include the shard path in the referer field when receiving stat updates.

    • Added a new config option, rows_per_shard, to specify how many objects should be in each shard when scanning for ranges. The default is shard_container_threshold / 2, preserving existing behavior.

    • Added a new config option, minimum_shard_size. When scanning for shard ranges, if the final shard would otherwise contain fewer than this many objects, the previous shard will instead be expanded to the end of the namespace (and so may contain up to rows_per_shard + minimum_shard_size objects). This reduces the number of small shards generated. The default value is rows_per_shard / 5.

    • The sharder now correctly identifies and fails audits for shard ranges that overlap exactly.

    • The sharder and swift-manage-shard-ranges now consider total row count (instead of just object count) when deciding whether a shard is a candidate for shrinking.

    • If the sharder encounters shard range gaps while cleaving, it will now log an error and halt sharding progress. Previously, rows may not have been moved properly, leading to data loss.

    • Sharding cycle time and last-completion time are now available via swift-recon.

    • Fixed an issue where resolving overlapping shard ranges via shrinking could prematurely mark created or cleaved shards as active.

  • S3 API improvements:

    • Added an option, ratelimit_as_client_error, to return 429s for rate-limited responses. Several clients/SDKs have seem to support retries with backoffs on 429, and having it as a client error cleans up logging and metrics. By default, Swift will respond 503, matching AWS documentation.

    • Fixed a server error in bucket listings when s3_acl is enabled and staticweb is configured for the container.

    • Fixed a server error when a client exceeds client_timeout during an upload. Now, a RequestTimeout error is correctly returned.

    • Fixed a server error when downloading multipart uploads/static large objects that have missing or inaccessible segments. This is a state that cannot arise in AWS, so a new BrokenMPU error is returned, indicating that retrying the request is unlikely to succeed.

    • Fixed several issues with the prefix, marker, and delimiter parameters that would be mirrored back to clients when listing buckets.

  • Partition power increase fixes:

    • The relinker now performs eventlet-hub selection the same way as other daemons. In particular, epolls will no longer be selected, as it seemed to cause occassional hangs.

    • Partitions that encountered errors during relinking are no longer marked as completed in the relinker state file. This ensures that a subsequent relink will retry the failed partitions.

    • Partition cleanup is more robust, decreasing the likelihood of leaving behind mostly-empty partitions from the old partition power.

    • Improved relinker progress logging, and started collecting progress information for swift-recon.

    • Cleanup is more robust to files and directories being deleted by another process.

    • The relinker better handles data found from earlier partition power increases.

    • The relinker better handles tombstones found for the same object but with different inodes.

    • The reconciler now defers working on policies that have a partition power increase in progress to avoid issues with concurrent writes.

  • Erasure coding fixes:

    • Added the ability to quarantine EC fragments that have no (or few) other fragments in the cluster. A new configuration option, quarantine_threshold, in the reconstructor controls the point at the fragment will be quarantined; the default (0) will never quarantine. Only fragments older than quarantine_age (default: reclaim_age) may be quarantined. Before quarantining, the reconstructor will attempt to fetch fragments from handoff nodes in addition to the usual primary nodes; a new request_node_count option (default 2 * replicas) limits the total number of nodes to contact.

    • Added a delay before deleting non-durable data. A new configuration option, commit_window in the [DEFAULT] section of object-server.conf, adjusts this delay; the default is 60 seconds. This improves the durability of both back-dated PUTs (from the reconciler or container-sync, for example) and fresh writes to handoffs by preventing the reconstructor from deleting data that the object-server was still writing.

    • Improved proxy-server and object-reconstructor logging when data cannot be reconstructed.

    • Fixed an issue where some but not all fragments having metadata applied could prevent reconstruction of missing fragments.

    • Server-side copying of erasure-coded data to a replicated policy no longer copies EC sysmeta. The previous behavior had no material effect, but could confuse operators examining data on disk.

  • Python 3 fixes:

    • Fixed a server error when performing a PUT authorized via tempurl with some proxy pipelines.

    • Fixed a server error during GET of a symlink with some proxy pipelines.

    • Fixed an issue with logging setup when /dev/log doesn’t exist or is not a UNIX socket.

  • The dark-data audit watcher now skips objects younger than a new configurable grace_age period. This avoids issues where data could be flagged, quarantined, or deleted because of listing consistency issues. The default is one week.

  • The dark-data audit watcher now requires that all primary locations for an object’s container agree that the data does not appear in listings to consider data “dark”. Previously, a network partition that left an object node isolated could cause it to quarantine or delete all of its data.

  • EPIPE errors no longer log tracebacks.

  • The account and container auditors now log and update recon before going to sleep.

  • The object-expirer logs fewer client disconnects.

  • swift-recon-cron now includes the last time it was run in the recon information.

  • EIO errors during read now cause object diskfiles to be quarantined.

  • The formpost middleware now properly supports uploading multiple files with different content-types.

  • Various other minor bug fixes and improvements.