CHANGELOG-3.3.md

v3.3.3 (TBD)

See code changes and v3.3 upgrade guide for any breaking changes.

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.

Fixed: v3

• TODO: Fix compaction interval calculation.
  • Previously, --auto-compaction-mode=periodic --auto-compaction-retention=10h automatically Compact on latest revision at first 10-hour and every 1-hour, whether it succeeds or not.
  • Now, it correctly reset its interval when Compact operation succeeds.
  • The failed Compact operation will still be retried in 1/10 of interval.
  • e.g. 10h compact interval will be retried in 1-hour on failure.
  • Document...

Metrics, Monitoring

• Add missing etcd_network_peer_sent_failures_total count.

Go

• Compile with Go 1.9.4.

v3.3.2 (2018-03-08)

See code changes and v3.3 upgrade guide for any breaking changes.

Fixed: v3

• Fix server panic on invalid Election Proclaim/Resign HTTP(S) requests.
  • Previously, wrong-formatted HTTP requests to Election API could trigger panic in etcd server.
  • e.g. curl -L http://localhost:2379/v3/election/proclaim -X POST -d '{"value":""}', curl -L http://localhost:2379/v3/election/resign -X POST -d '{"value":""}'.
• Fix revision-based compaction retention parsing.
  • Previously, --auto-compaction-mode revision --auto-compaction-retention 1 was translated to revision retention 3600000000000.
  • Now, --auto-compaction-mode revision --auto-compaction-retention 1 is correctly parsed as revision retention 1.
• Prevent overflow by large TTL values for Lease Grant.
  • TTL parameter to Grant request is unit of second.
  • Leases with too large TTL values exceeding math.MaxInt64 expire in unexpected ways.
  • Server now returns rpctypes.ErrLeaseTTLTooLarge to client, when the requested TTL is larger than 9,000,000,000 seconds (which is >285 years).
  • Again, etcd Lease is meant for short-periodic keepalives or sessions, in the range of seconds or minutes. Not for hours or days!
• Enable etcd server raft.Config.CheckQuorum when starting with ForceNewCluster.

Fixed: v2

• Fix v2 proxy leaky HTTP requests.

Go

• Compile with Go 1.9.4.

v3.3.1 (2018-02-12)

See code changes and v3.3 upgrade guide for any breaking changes.

Improved

• Add warnings on requests taking too long.
  • e.g. etcdserver: read-only range request "key:\"\\000\" range_end:\"\\000\" " took too long [3.389041388s] to execute

Fixed: v3

• 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.

Go

• Compile with Go 1.9.4.

v3.3.0 (2018-02-01)

See code changes and v3.3 upgrade guide for any breaking changes.

• v3.3.0-rc.4 (2018-01-22), see code changes.
• v3.3.0-rc.3 (2018-01-17), see code changes.
• v3.3.0-rc.2 (2018-01-11), see code changes.
• v3.3.0-rc.1 (2018-01-02), see code changes.
• v3.3.0-rc.0 (2017-12-20), see code changes.

Improved

• Use coreos/bbolt to replace boltdb/bolt.
  • Fix etcd database size grows until mvcc: database space exceeded.
• Support database size larger than 8GiB (8GiB is now a suggested maximum size for normal environments)
• Reduce memory allocation on Range operations.
• Rate limit and randomize lease revoke on restart or leader elections.
  • Prevent spikes in Raft proposal rate.
• Support clientv3 balancer failover under network faults/partitions.
• Better warning on mismatched --initial-cluster flag.
  • etcd compares --initial-advertise-peer-urls against corresponding --initial-cluster URLs with forward-lookup.
  • If resolved IP addresses of --initial-advertise-peer-urls and --initial-cluster do not match (e.g. due to DNS error), etcd will exit with errors.
    • v3.2 error: --initial-cluster must include s1=https://s1.test:2380 given --initial-advertise-peer-urls=https://s1.test:2380.
    • v3.3 error: failed to resolve https://s1.test:2380 to match --initial-cluster=s1=https://s1.test:2380 (failed to resolve "https://s1.test:2380" (error ...)).

Breaking Changes

• Require google.golang.org/grpc v1.7.4 or v1.7.5.
  • Deprecate metadata.Incoming/OutgoingContext.
  • Deprecate grpclog.Logger, upgrade to grpclog.LoggerV2.
  • Deprecate grpc.ErrClientConnTimeout errors in clientv3.
  • Use MaxRecvMsgSize and MaxSendMsgSize to limit message size, in etcd server.
• Translate gRPC status error in v3 client Snapshot API.
• v3 etcdctl lease timetolive LEASE_ID on expired lease now prints "lease LEASE_ID already expired".
  • <=3.2 prints "lease LEASE_ID granted with TTL(0s), remaining(-1s)".

Dependency

• Upgrade boltdb/bolt from v1.3.0 to coreos/bbolt v1.3.1-coreos.6.
• Upgrade google.golang.org/grpc from v1.2.1 to v1.7.5.
• Upgrade github.com/ugorji/go/codec to v1.1, and regenerate v2 client.
• Upgrade github.com/ugorji/go/codec to ugorji/go@54210f4, and regenerate v2 client.
• Upgrade github.com/grpc-ecosystem/grpc-gateway from v1.2.2 to v1.3.0.
• Upgrade golang.org/x/crypto/bcrypt to golang/crypto@6c586e1.

Metrics, Monitoring

• Add etcd --listen-metrics-urls flag for additional /metrics endpoints.
  • Useful for bypassing critical APIs when monitoring etcd.
• Add etcd_server_version Prometheus metric.
  • To replace Kubernetes etcd-version-monitor.
• Add etcd_debugging_mvcc_db_compaction_keys_total Prometheus metric.
• Add etcd_debugging_server_lease_expired_total Prometheus metric.
  • To improve lease revoke monitoring.
• Document Prometheus 2.0 rules.
• Initialize gRPC server metrics with zero values.
• Fix range/put/delete operation metrics with transaction.
  • etcd_debugging_mvcc_range_total
  • etcd_debugging_mvcc_put_total
  • etcd_debugging_mvcc_delete_total
  • etcd_debugging_mvcc_txn_total
• Fix etcd_debugging_mvcc_keys_total on restore.
• Fix etcd_debugging_mvcc_db_total_size_in_bytes on restore.
  • Also change to prometheus.NewGaugeFunc.

Security, Authentication

See security doc for more details.

• Add CRL based connection rejection to manage revoked certs.
• Document TLS authentication changes.
  • Server accepts connections if IP matches, without checking DNS entries. For instance, if peer cert contains IP addresses and DNS names in Subject Alternative Name (SAN) field, and the remote IP address matches one of those IP addresses, server just accepts connection without further checking the DNS names.
  • Server supports reverse-lookup on wildcard DNS SAN. For instance, if peer cert contains only DNS names (no IP addresses) in Subject Alternative Name (SAN) field, server first reverse-lookups the remote IP address to get a list of names mapping to that address (e.g. nslookup IPADDR). Then accepts the connection if those names have a matching name with peer cert's DNS names (either by exact or wildcard match). If none is matched, server forward-lookups each DNS entry in peer cert (e.g. look up example.default.svc when the entry is *.example.default.svc), and accepts connection only when the host's resolved addresses have the matching IP address with the peer's remote IP address.
• Add etcd --peer-cert-allowed-cn flag.
  • To support CommonName(CN) based auth for inter peer connection.
• Swap priority of cert CommonName(CN) and username + password.
  • To address "username and password specified in the request should take priority over CN in the cert".
• Protect lease revoke with auth.
• Provide user's role on auth permission error.
• Fix auth store panic with disabled token.

Added: etcd

• Add --experimental-initial-corrupt-check flag to check cluster database hashes before serving client/peer traffic.
  • --experimental-initial-corrupt-check=false by default.
  • v3.4 will enable --initial-corrupt-check=true by default.
• Add --experimental-corrupt-check-time flag to raise corrupt alarm monitoring.
  • --experimental-corrupt-check-time=0s disabled by default.
• Add --experimental-enable-v2v3 flag to emulate v2 API with v3.
  • --experimental-enable-v2v3=false by default.
• Add --max-txn-ops flag to configure maximum number operations in transaction.
• Add --max-request-bytes flag to configure maximum client request size.
  • If not configured, it defaults to 1.5 MiB.
• Add --client-crl-file, --peer-crl-file flags for Certificate revocation list.
• Add --peer-cert-allowed-cn flag to support CN-based auth for inter-peer connection.
• Add --listen-metrics-urls flag for additional /metrics endpoints.
  • Support additional (non) TLS /metrics endpoints for a TLS-enabled cluster.
  • e.g. --listen-metrics-urls=https://localhost:2378,http://localhost:9379 to serve /metrics in secure port 2378 and insecure port 9379.
  • Useful for bypassing critical APIs when monitoring etcd.
• Add --auto-compaction-mode flag to support revision-based compaction.
• Change --auto-compaction-retention flag to accept string values with finer granularity.
  • e.g. --auto-compaction-mode=periodic --auto-compaction-retention=30m automatically Compact on latest revision every 30-minute.
  • e.g. --auto-compaction-mode=revision --auto-compaction-retention=1000 automatically Compact on "latest revision" - 1000 every 5-minute (when latest revision is 30000, compact on revision 29000).
• Add --grpc-keepalive-min-time, --grpc-keepalive-interval, --grpc-keepalive-timeout flags to configure server-side keepalive policies.
• Serve /health endpoint as unhealthy when alarm (e.g. NOSPACE) is raised or there's no leader.
  • Define etcdhttp.Health struct with JSON encoder.
  • Note that "health" field is string type, not bool.
    • e.g. {"health":"false"}, {"health":"true"}
  • Remove "errors" field since v3.3.0-rc.3 (did exist only in v3.3.0-rc.0, v3.3.0-rc.1, v3.3.0-rc.2).
• Move logging setup to embed package
  • Disable gRPC server info-level logs by default (can be enabled with etcd --debug flag).
• Use monotonic time in Go 1.9 for lease package.
• Warn on empty hosts in advertise URLs.
  • Address advertise client URLs accepts empty hosts.
  • etcd v3.4 will exit on this error.
    • e.g. --advertise-client-urls=http://:2379.
• Warn on shadowed environment variables.
  • Address error on shadowed environment variables.
  • etcd v3.4 will exit on this error.

Added: API

• Support ranges in transaction comparisons for disconnected linearized reads.
• Add nested transactions to extend proxy use cases.
• Add lease comparison target in transaction.
• Add lease list.
• Add hash by revision for better corruption checking against boltdb.

Added: clientv3

• Add health balancer to fix watch API hangs, improve endpoint switch under network faults.
• Refactor balancer and add client-side keepalive pings to handle network partitions.
• Add MaxCallSendMsgSize and MaxCallRecvMsgSize fields to clientv3.Config.
  • Fix exceeded response size limit error in client-side.
  • Address kubernetes#51099.
    • In previous versions(v3.2.10, v3.2.11), client response size was limited to only 4 MiB.
  • MaxCallSendMsgSize default value is 2 MiB, if not configured.
  • MaxCallRecvMsgSize default value is math.MaxInt32, if not configured.
• Accept Compare_LEASE in clientv3.Compare.
• Add LeaseValue helper to Cmp LeaseID values in Txn.
• Add MoveLeader to Maintenance.
• Add HashKV to Maintenance.
• Add Leases to Lease.
• Add clientv3/ordering for enforce ordering in serialized requests.

Fixed: clientv3

• Fix "put at-most-once" violation.
• Fix WatchResponse.Canceled on compacted watch request.
• Fix concurrency/stm Put with serializable snapshot.
  • Use store revision from first fetch to resolve write conflicts instead of modified revision.

Added: v3 etcdctl

• Add --discovery-srv flag.
• Add --keepalive-time, --keepalive-timeout flags.
• Add lease list command.
• Add lease keep-alive --once flag.
• Make lease timetolive LEASE_ID on expired lease print lease LEASE_ID already expired.
  • <=3.2 prints lease LEASE_ID granted with TTL(0s), remaining(-1s).
• Add snapshot restore --wal-dir flag.
• Add defrag --data-dir flag.
• Add move-leader command.
• Add endpoint hashkv command.
• Add endpoint --cluster flag, equivalent to v2 etcdctl cluster-health.
• Make endpoint health command terminate with non-zero exit code on unhealthy status.
• Add lock --ttl flag.
• Support watch [key] [range_end] -- [exec-command…], equivalent to v2 etcdctl exec-watch.
  • Make watch -- [exec-command] set environmental variables ETCD_WATCH_REVISION, ETCD_WATCH_EVENT_TYPE, ETCD_WATCH_KEY, ETCD_WATCH_VALUE for each event.
• Support watch with environmental variables ETCDCTL_WATCH_KEY and ETCDCTL_WATCH_RANGE_END.
• Enable clientv3.WithRequireLeader(context.Context) for watch command.
• Print "del" instead of "delete" in txn interactive mode.
• Print ETCD_INITIAL_ADVERTISE_PEER_URLS in member add.

Fixed: v3 etcdctl

• Handle empty key permission in etcdctl.

Added: v2 etcdctl

• Add backup --with-v3 flag.

Added: grpc-proxy

• Add grpc-proxy start --experimental-leasing-prefix flag.
  • For disconnected linearized reads.
  • Based on V system leasing.
  • See "Disconnected consistent reads with etcd" blog post.
• Add grpc-proxy start --experimental-serializable-ordering flag.
  • To ensure serializable reads have monotonically increasing store revisions across endpoints.
• Add grpc-proxy start --metrics-addr flag for an additional /metrics endpoint.
  • Set --metrics-addr=http://[HOST]:9379 to serve /metrics in insecure port 9379.
• Serve /health endpoint in grpc-proxy.
• Add grpc-proxy start --debug flag.
• Add grpc-proxy start --max-send-bytes flag to configure maximum client request size.
• Add grpc-proxy start --max-recv-bytes flag to configure maximum client request size.

Fixed: grpc-proxy

• Fix Snapshot API error handling.
• Fix KV API PrevKv flag handling.
• Fix KV API KeysOnly flag handling.

Added: gRPC gateway

• Replace gRPC gateway /v3alpha with /v3beta.
  • To deprecate /v3alpha in v3.4.
• Support "authorization" token.
• Support websocket for bi-directional streams.
  • Fix Watch API with gRPC gateway.
• Upgrade gRPC gateway to v1.3.0.

Fixed: v3

• Fix backend database in-memory index corruption issue on restore (only 3.2.0 is affected).
• Fix watch restore from snapshot.
• Fix mvcc/backend.defragdb nil-pointer dereference on create bucket failure.
• Fix server crash on invalid transaction request from gRPC gateway.
• Prevent server panic from member update/add with wrong scheme URLs.
• Make peer dial timeout longer.
  • See coreos/etcd-operator#1300 for more detail.
• Make server wait up to request time-out with pending RPCs.
• Fix grpc.Server panic on GracefulStop with TLS-enabled server.
• Fix "multiple peer URLs cannot start" issue.
• Fix server-side auth so concurrent auth operations do not return old revision error.
• Handle WAL renaming failure on Windows.
• Upgrade coreos/go-systemd to v15 (see https://github.com/coreos/go-systemd/releases/tag/v15).

Fixed: v2

• Fail-over v2 client to next endpoint on oneshot failure.
• Put back /v2/machines endpoint for python-etcd wrapper.

Package raft

• Add non-voting member.
  • To implement Raft thesis 4.2.1 Catching up new servers.
  • Learner node does not vote or promote itself.

Other

• Support previous two minor versions (see our new release policy).
• v3.3.x is the last release cycle that supports ACI.
  • AppC was officially suspended, as of late 2016.
  • acbuild is not maintained anymore.
  • *.aci files won't be available from etcd v3.4 release.
• Add container registry gcr.io/etcd-development/etcd.
  • quay.io/coreos/etcd is still supported as secondary.

Go

• Require Go 1.9+.
• Compile with Go 1.9.3.
• Deprecate golang.org/x/net/context.