github.com/uber/ringpop-go

• Fix: LookupN returns ring node destinations in ring order #211
• Fix: Use lower case sirupsen/logrus import #208
• Feature: Added GetNClients to router #212

• Allow requiresAppInPing to be configured #209

• Fix: Add option to enforce identical app name in pings #206

Merge branch 'release-0.8.2'

add changes for v0.8.1 to CHANGELOG.md (#202)

• Fix: ineffectual assignments #193
• Fix: Make lookups consistent on hash collisions #196
• Feature: Self-eviction #177
• Feature: Identity Carry Over #188 #189 #190 #191 #192 #194 #195
• Travis: Remove Go 1.5 support #187

Release notes

Identity Carry Over

Identity carry over provides a way to manually configure the identity of a member on the hashring. By changing the identity to be something else than its address, it becomes possible to guarantee ring equality before and after deploys in a dynamic environment (e.g. mesos).

Self Eviction

By calling ringpop.SelfEvict on shutdown, a member will declare itself as faulty and gossips this to the other members. This removes the time window where it would be marked as suspect; in this way removing the time where other members considered it to be part of the ring while it was not responding anymore.

Breaking change to the identity-option

Prior to ringpop v0.8.0 the address was used as the identity of a member. Starting with version v0.8.0, it's possible to configure a separate identity. As a result, the behaviour of the Identity and IdentityResolverFunc has been changed. The Identity option now configures the identity of a member and will return an error when it matches an ip:port; services that were using Identity or IdentityResolverFunc should now use the Address and AddressResolverFunc options. You could use the following gofmt snippets to easily refactor:

gofmt -r 'ringpop.Identity(a) -> ringpop.Address(a)' -w .
gofmt -r 'ringpop.IdentityResolverFunc(a) -> ringpop.AddressResolverFunc(a)' -w .

• Fix: Header leaking on the forwarding path caused calls to own endpoints to not be sharded when the same context was used while making the call #197

Release notes

Header leaking

When applications use their incoming context blindly in an outgoing call it uses the same tchannel headers for the outgoing call as the incoming call had, causing incoming headers to be leaked in the outgoing call. Since most applications don't use headers there is nothing to worry about. However the forwarding path of ringpop uses a header to indicate a call has been forwarded. This header prevents indefinite forwarding loops to occur when applications fail to converge on ownership.

With this fix the header indicating a forwarded call will not be leaked to the application. This makes it possible for applications to use the incoming context on a call to a sharded endpoint on their own or another ringpop servers service an correctly route the request.

• Feature: Added label support to ringpop for nodes to annotate themselves with more information #167 #171 #172
• Maintainability: Refactored internal representation of member state for more flexible reincarnation and state change of a member #159 #161
• Fix: Make sure ringpop is listening for requests before bootstrapping #176 #146
• Fix: Added support for imports in .thrift files in generated code for thrift forwarding #162
• Fix: Mark generated code as being generated for suppression in diffs #169
• Fix: Be more specific in the functionality required from TChannel #166
• Tests: Run all tests on go 1.7 #179
• Tests: More stable unit tests, integration tests and race detector tests. Races are now mandatory tests on ci #164 #178 #181 #182
• Tests: All examples are tested on every pull request #157 #170

Release notes

Change to ringpop interface

The ringpop interface changed two existing functions GetReachableMembers and CountReachableMembers that now take a variadic argument of type swim.MemberPredicate instead of no arguments. This does not change the usage of these functions, but does change the type of the function. This might cause custom declared interfaces to not match ringpop anymore. The solution is to change these functions in the interface used to match the current signature.

Previously the signature was:

  GetReachableMembers() ([]string, error)
  CountReachableMembers() (int, error)

The current signature is:

  GetReachableMembers(predicates ...swim.MemberPredicate) ([]string, error)
  CountReachableMembers(predicates ...swim.MemberPredicate) (int, error)

Deprecated RegisterListener

Due to a refactor in how event emitting is done the RegisterListener method is deprecated. Even though it still works and behaves as previously it will start logging warnings. Since this code is not on the hot path only little log volume is expected. Instead of this function it is now advised to use AddListener. This function also returns if the listener has been added or not.

• Fix: add 1-buffer for error channels, prevents leaking goroutines. #140
• Feature: support forwarding headers. #141
• Feature: testpop takes an additional -stats-udp or -stats-file flag that can be used to emit statsd messages to a file or over the network. #144
• Fix: race condition when loading hostlist in discover provider. #145
• Testing: add suspect, faulty and tombstope period command-line flags to testpop. #148
• Fix: use oneself as a source when creating a change for reincarnation. #150
• Maintainability: move from godep to Glide. #151
• Maintainability: emit lookup and lookupn stats and add a lookupn-event. #152.
• Fix: do not reincarnate twice unnecessarily. #153

• Feature: Automatic healing of fully partitioned rings that could be cause by temporary network failure. #135 #128 #129
• Fix: Fullsyncs are now executed in both directions to prevent persistent asymmetrical partitions. #134
• Fix: Overcome protocol incompatibilities in the dissemination of tombstones for the reaping of faulty nodes. #133 #132
• Fix: Leaking goroutines on an error response after a timeout. #140
• Maintainability: Refactor of internal use of the Discovery Provider. #130
• Testing: Pin mockery to a specific version for testing stability. #136
• Testing: Add Go race detector on CI. #137

Release notes

Deploying from older versions

It is advised to complete the deployment of this version within 24 hours after the first node is upgraded. Since the reaping of faulty nodes is added to this release a node that upgraded to this version will mark all the faulty members of the ringpop cluster as tombstones (the new state introduced for the reaping of faulty nodes) 24 hours after the deploy. If older versions of ringpop run in a cluster that starts declaring these tombstones the cluster will jump in endless fullsyncs mode. Ringpop operates normally under these conditions but extra load on both network and CPU are in effect during this time. The fullsyncs will automatically resolve as soon as all members are upgraded to this version. Same might happen during a partial rollback that operates for a longer period of time.

• Reverting reaping faulty nodes feature temporarily while investigate backwards compatibility issues.

• Feature: Faulty nodes are now automatically reaped from nodes' membership lists after (24 hours by default). #123
• New options for controlling suspect and reaping times. #123
• Add new Ready and Destroyed events to ringpop. #125
• Add additional logging to bring ringpop-go on par with ringpop-node log messages. #116
• Fix bug where Ringpop automatically added itself to the bootstrap hosts for host-based bootstrapping, but not other bootstrapping methods. #120
• Fix race condition where membership and hashring could be inconsistent with each other. #112
• Remove File and Host options from bootstrap options in favor of DiscoverProvider interface. #120
• Add Go 1.6 to testing on CI

Release notes

Version incompatibility in protocol

Since 0.4.0 introduces a new node/member state, 0.4.0 is not backwards-compatible with previous versions.

Note rolling upgrades with older versions do work, but undefined behaviour will occur if two versions run in parallel for longer than the FaultyPeriod (default 24 hours).

Changes to Bootstrap

This release contains a breaking change to the options provided to the ringpop.Bootstrap call.

BootstrapOptions.File and BootstrapOptions.Hosts have been replaced with BootstrapOptions.DiscoverProvider. DiscoverProvider is an interface which requires a single method:

type DiscoverProvider interface {
    Hosts() ([]string, error)
}

Ringpop comes with DiscoverProviders for the previous File and Hosts options out of the box.

To upgrade if you were previously using File:

+       "github.com/uber/ringpop-go/discovery/jsonfile"
...
-       bootstrapOpts.File = *hostfile
+       bootstrapOpts.DiscoverProvider = jsonfile.New(*hostfile)

For static Hosts:

+       "github.com/uber/ringpop-go/discovery/statichosts"
...
-       bootstrapOpts.Hosts = []string{"127.0.0.1:3000", "127.0.0.1:3001"}
+       bootstrapOpts.DiscoverProvider = statichosts.New("127.0.0.1:3000", "127.0.0.1:3001")

• Fix "keys have diverged" forwarding error for retries #69
• Fix possible race in disseminator #86
• Fix possible issue with leave state not being applied correctly #94
• Fix issues where unnecessary full syncs could occur #95, #97
• Improvements to join:
  • Join retries now have exponential backoff #68
  • Improved resilience to possible partitions at startup #65
  • Reduce network chatter on join #85
• Hashring performance improvements (see discussion on #58) #58
• Revamped logging; new logger options #83
• New stats to aid partition detection #92, #104
• Improved test coverage across the board
• Update and test with latest TChannel (v1.0.3) #103
• Various fixes and improvements to test infrastructure

• Fix retry mechanism for forwarded requests. When multiple keys are forwarded and a retry is attempted, the retry would fail with a "key destinations have diverged" error.

• Fix goroutine leakage on forwarded requests that time out