Previous change logs can be found at CHANGELOG-3.0.

The minimum recommended etcd versions to run in production are 3.1.11+, 3.2.26+, and 3.3.11+.

v3.1.21 (2019-TBD)

etcdctl v3

• Strip out insecure endpoints from DNS SRV records when using discovery with etcdctl v2
• Add etcdctl endpoint health --write-out support.
  • Previously, etcdctl endpoint health --write-out json did not work.
  • The command output is changed. Previously, if endpoint is unreachable, the command output is "<endpoint> is unhealthy: failed to connect: <error message>". This change unified the error message, all error types now have the same output "<endpoint> is unhealthy: failed to commit proposal: <error message>".

Metrics, Monitoring

See List of metrics for all metrics per release.

Note that any etcd_debugging_* metrics are experimental and subject to change.

• Fix bug where db_compaction_total_duration_milliseconds metric incorrectly measured duration as 0.

v3.1.20 (2018-10-10)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

Improved

• Improve "became inactive" warning log, which indicates message send to a peer failed.
• Improve read index wait timeout warning log, which indicates that local node might have slow network.
• Add gRPC interceptor for debugging logs; enable etcd --debug flag to see per-request debug information.
• Add consistency check in snapshot status. If consistency check on snapshot file fails, snapshot status returns "snapshot file integrity check failed..." error.

Metrics, Monitoring

See List of metrics for all metrics per release.

Note that any etcd_debugging_* metrics are experimental and subject to change.

• Improve etcd_network_peer_round_trip_time_seconds Prometheus metric to track leader heartbeats.
  • Previously, it only samples the TCP connection for snapshot messages.
• Display all registered gRPC metrics at start.
• Add etcd_snap_db_fsync_duration_seconds_count Prometheus metric.
• Add etcd_snap_db_save_total_duration_seconds_bucket Prometheus metric.
• Add etcd_network_snapshot_send_success Prometheus metric.
• Add etcd_network_snapshot_send_failures Prometheus metric.
• Add etcd_network_snapshot_send_total_duration_seconds Prometheus metric.
• Add etcd_network_snapshot_receive_success Prometheus metric.
• Add etcd_network_snapshot_receive_failures Prometheus metric.
• Add etcd_network_snapshot_receive_total_duration_seconds Prometheus metric.
• Add etcd_server_id Prometheus metric.
• Add etcd_server_health_success Prometheus metric.
• Add etcd_server_health_failures Prometheus metric.
• Add etcd_server_read_indexes_failed_total Prometheus metric.

client v3

• Fix logic on release lock key if cancelled in clientv3/concurrency package.

Go

• Compile with Go 1.8.7.

v3.1.19 (2018-07-24)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

Improved

• Improve Raft Read Index timeout warning messages.

Metrics, Monitoring

See List of metrics for all metrics per release.

Note that any etcd_debugging_* metrics are experimental and subject to change.

• Add etcd_server_go_version Prometheus metric.
• Add etcd_server_slow_read_indexes_total Prometheus metric.
• Add etcd_server_quota_backend_bytes Prometheus metric.
  • Use it with etcd_mvcc_db_total_size_in_bytes and etcd_mvcc_db_total_size_in_use_in_bytes.
  • etcd_server_quota_backend_bytes 2.147483648e+09 means current quota size is 2 GB.
  • etcd_mvcc_db_total_size_in_bytes 20480 means current physically allocated DB size is 20 KB.
  • etcd_mvcc_db_total_size_in_use_in_bytes 16384 means future DB size if defragment operation is complete.
  • etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes is the number of bytes that can be saved on disk with defragment operation.
• Add etcd_mvcc_db_total_size_in_bytes Prometheus metric.
  • In addition to etcd_debugging_mvcc_db_total_size_in_bytes.
• Add etcd_mvcc_db_total_size_in_use_in_bytes Prometheus metric.
  • Use it with etcd_mvcc_db_total_size_in_bytes and etcd_mvcc_db_total_size_in_use_in_bytes.
  • etcd_server_quota_backend_bytes 2.147483648e+09 means current quota size is 2 GB.
  • etcd_mvcc_db_total_size_in_bytes 20480 means current physically allocated DB size is 20 KB.
  • etcd_mvcc_db_total_size_in_use_in_bytes 16384 means future DB size if defragment operation is complete.
  • etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes is the number of bytes that can be saved on disk with defragment operation.

client v3

• Fix lease keepalive interval updates when response queue is full.
  • If <-chan *clientv3LeaseKeepAliveResponse from clientv3.Lease.KeepAlive was never consumed or channel is full, client was sending keepalive request every 500ms instead of expected rate of every "TTL / 3" duration.

Go

• Compile with Go 1.8.7.

v3.1.18 (2018-06-15)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

Metrics, Monitoring

See List of metrics for all metrics per release.

Note that any etcd_debugging_* metrics are experimental and subject to change.

• Add etcd_server_version Prometheus metric.
  • To replace Kubernetes etcd-version-monitor.

Go

• Compile with Go 1.8.7.

v3.1.17 (2018-06-06)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

etcd server

• Fix v3 snapshot recovery.
  • A follower receives a leader snapshot to be persisted as a [SNAPSHOT-INDEX].snap.db file on disk.
  • Now, server ensures that the incoming snapshot be persisted on disk before loading it.
  • Otherwise, index mismatch happens and triggers server-side panic (e.g. newer WAL entry with outdated snapshot index).

Go

• Compile with Go 1.8.7.

v3.1.16 (2018-05-31)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

etcd server

• Fix mvcc server panic from restore operation.
  • Let's assume that a watcher had been requested with a future revision X and sent to node A that became network-partitioned thereafter. Meanwhile, cluster makes progress. Then when the partition gets removed, the leader sends a snapshot to node A. Previously if the snapshot's latest revision is still lower than the watch revision X, etcd server panicked during snapshot restore operation.
  • Now, this server-side panic has been fixed.

Go

• Compile with Go 1.8.7.

v3.1.15 (2018-05-09)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

etcd server

• Purge old *.snap.db snapshot files.
  • Previously, etcd did not respect --max-snapshots flag to purge old *.snap.db files.
  • Now, etcd purges old *.snap.db files to keep maximum --max-snapshots number of files on disk.

Go

• Compile with Go 1.8.7.

v3.1.14 (2018-04-24)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

Metrics, Monitoring

See List of metrics for all metrics per release.

Note that any etcd_debugging_* metrics are experimental and subject to change.

• Add etcd_server_is_leader Prometheus metric.

etcd server

• Add --initial-election-tick-advance flag to configure initial election tick fast-forward.
  • By default, --initial-election-tick-advance=true, then local member fast-forwards election ticks to speed up "initial" leader election trigger.
  • This benefits the case of larger election ticks. For instance, cross datacenter deployment may require longer election timeout of 10-second. If true, local node does not need wait up to 10-second. Instead, forwards its election ticks to 8-second, and have only 2-second left before leader election.
  • Major assumptions are that: cluster has no active leader thus advancing ticks enables faster leader election. Or cluster already has an established leader, and rejoining follower is likely to receive heartbeats from the leader after tick advance and before election timeout.
  • However, when network from leader to rejoining follower is congested, and the follower does not receive leader heartbeat within left election ticks, disruptive election has to happen thus affecting cluster availabilities.
  • Now, this can be disabled by setting --initial-election-tick-advance=false.
  • Disabling this would slow down initial bootstrap process for cross datacenter deployments. Make tradeoffs by configuring --initial-election-tick-advance at the cost of slow initial bootstrap.
  • If single-node, it advances ticks regardless.
  • Address disruptive rejoining follower node.

Go

• Compile with Go 1.8.7.

v3.1.13 (2018-03-29)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

Improved

• Adjust election timeout on server restart to reduce disruptive rejoining servers.
  • Previously, etcd fast-forwards election ticks on server start, with only one tick left for leader election. This is to speed up start phase, without having to wait until all election ticks elapse. Advancing election ticks is useful for cross datacenter deployments with larger election timeouts. However, it was affecting cluster availability if the last tick elapses before leader contacts the restarted node.
  • Now, when etcd restarts, it adjusts election ticks with more than one tick left, thus more time for leader to prevent disruptive restart.

Metrics, Monitoring

See List of metrics for all metrics per release.

Note that any etcd_debugging_* metrics are experimental and subject to change.

• Add missing etcd_network_peer_sent_failures_total count.

Go

• Compile with Go 1.8.7.

v3.1.12 (2018-03-08)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

etcd server

• Fix mvcc "unsynced" watcher restore operation.
  • "unsynced" watcher is watcher that needs to be in sync with events that have happened.
  • That is, "unsynced" watcher is the slow watcher that was requested on old revision.
  • "unsynced" watcher restore operation was not correctly populating its underlying watcher group.
  • Which possibly causes missing events from "unsynced" watchers.
  • A node gets network partitioned with a watcher on a future revision, and falls behind receiving a leader snapshot after partition gets removed. When applying this snapshot, etcd watch storage moves current synced watchers to unsynced since sync watchers might have become stale during network partition. And reset synced watcher group to restart watcher routines. Previously, there was a bug when moving from synced watcher group to unsynced, thus client would miss events when the watcher was requested to the network-partitioned node.

Go

• Compile with Go 1.8.7.

v3.1.11 (2017-11-28)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

etcd server

• #8411,#8806 backport "mvcc: sending events after restore"
• #8009,#8902 backport coreos/bbolt v1.3.1-coreos.5

Go

• Compile with Go 1.8.5.

v3.1.10 (2017-07-14)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

Added

• Tag docker images with minor versions.
  • e.g. docker pull quay.io/coreos/etcd:v3.1 to fetch latest v3.1 versions.

Go

• Compile with Go 1.8.3.
  • Fix panic on net/http.CloseNotify

v3.1.9 (2017-06-09)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

etcd server

• Allow v2 snapshot over 512MB.

Go

• Compile with Go 1.7.6.

v3.1.8 (2017-05-19)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

Go

• Compile with Go 1.7.5.

v3.1.7 (2017-04-28)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

Go

• Compile with Go 1.7.5.

v3.1.6 (2017-04-19)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

etcd server

• Fill in Auth API response header.
• Remove auth check in Status API.

Go

• Compile with Go 1.7.5.

v3.1.5 (2017-03-27)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

etcd server

• Fix raft memory leak issue.
• Fix Windows file path issues.

Other

• Add /etc/nsswitch.conf file to alpine-based Docker image.

Go

• Compile with Go 1.7.5.

v3.1.4 (2017-03-22)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

Go

• Compile with Go 1.7.5.

v3.1.3 (2017-03-10)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

etcd gateway

• Fix etcd gateway schema handling in DNS discovery.
• Fix sd_notify behaviors in gateway, grpc-proxy.

gRPC Proxy

• Fix sd_notify behaviors in gateway, grpc-proxy.

Other

• Use machine default host when advertise URLs are default values(localhost:2379,2380) AND if listen URL is 0.0.0.0.

Go

• Compile with Go 1.7.5.

v3.1.2 (2017-02-24)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

etcd gateway

• Fix etcd gateway with multiple endpoints.

Other

• Use IPv4 default host, by default (when IPv4 and IPv6 are available).

Go

• Compile with Go 1.7.5.

v3.1.1 (2017-02-17)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

Go

• Compile with Go 1.7.5.

v3.1.0 (2017-01-20)

See code changes and v3.1 upgrade guide for any breaking changes.

Again, before running upgrades from any previous release, please make sure to read change logs below and v3.1 upgrade guide.

Improved

• Faster linearizable reads (implements Raft read-index).
• v3 authentication API is now stable.

Breaking Changes

• Deprecated following gRPC metrics in favor of go-grpc-prometheus.
  • etcd_grpc_requests_total
  • etcd_grpc_requests_failed_total
  • etcd_grpc_active_streams
  • etcd_grpc_unary_requests_duration_seconds

Dependency

• Upgrade github.com/ugorji/go/codec to ugorji/go@9c7f9b7, and regenerate v2 client.

Security, Authentication

See security doc for more details.

• SRV records (e.g., infra1.example.com) must match the discovery domain (i.e., example.com) if no custom certificate authority is given.
  • TLSConfig.ServerName is ignored with user-provided certificates for backwards compatibility; to be deprecated.
  • For example, etcd --discovery-srv=example.com will only authenticate peers/clients when the provided certs have root domain example.com as an entry in Subject Alternative Name (SAN) field.

etcd server

• Automatic leadership transfer when leader steps down.
• etcd flags
  • --strict-reconfig-check flag is set by default.
  • Add --log-output flag.
  • Add --metrics flag.
• etcd uses default route IP if advertise URL is not given.
• Cluster rejects removing members if quorum will be lost.
• Discovery now has upper limit for waiting on retries.
• Warn on binding listeners through domain names; to be deprecated.
• v3.0 and v3.1 with --auto-compaction-retention=10 run periodic compaction on v3 key-value store for every 10-hour.
  • Compactor only supports periodic compaction.
  • Compactor records latest revisions every 5-minute, until it reaches the first compaction period (e.g. 10-hour).
  • In order to retain key-value history of last compaction period, it uses the last revision that was fetched before compaction period, from the revision records that were collected every 5-minute.
  • When --auto-compaction-retention=10, compactor uses revision 100 for compact revision where revision 100 is the latest revision fetched from 10 hours ago.
  • If compaction succeeds or requested revision has already been compacted, it resets period timer and starts over with new historical revision records (e.g. restart revision collect and compact for the next 10-hour period).
  • If compaction fails, it retries in 5 minutes.

client v3

• Add SetEndpoints method; update endpoints at runtime.
• Add Sync method; auto-update endpoints at runtime.
• Add Lease TimeToLive API; fetch lease information.
• replace Config.Logger field with global logger.
• Get API responses are sorted in ascending order by default.

etcdctl v3

• Add lease timetolive command.
• Add --print-value-only flag to get command.
• Add --dest-prefix flag to make-mirror command.
• get command responses are sorted in ascending order by default.

gRPC Proxy

• Experimental gRPC proxy feature.

Other

• recipes now conform to sessions defined in clientv3/concurrency.
• ACI has symlinks to /usr/local/bin/etcd*.

Go

• Compile with Go 1.7.4.