diff options
Diffstat (limited to 'vendor/github.com/hashicorp/memberlist/config.go')
| -rw-r--r-- | vendor/github.com/hashicorp/memberlist/config.go | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/vendor/github.com/hashicorp/memberlist/config.go b/vendor/github.com/hashicorp/memberlist/config.go new file mode 100644 index 000000000..2f43d14cb --- /dev/null +++ b/vendor/github.com/hashicorp/memberlist/config.go @@ -0,0 +1,288 @@ +package memberlist + +import ( + "io" + "log" + "os" + "time" +) + +type Config struct { + // The name of this node. This must be unique in the cluster. + Name string + + // Transport is a hook for providing custom code to communicate with + // other nodes. If this is left nil, then memberlist will by default + // make a NetTransport using BindAddr and BindPort from this structure. + Transport Transport + + // Configuration related to what address to bind to and ports to + // listen on. The port is used for both UDP and TCP gossip. It is + // assumed other nodes are running on this port, but they do not need + // to. + BindAddr string + BindPort int + + // Configuration related to what address to advertise to other + // cluster members. Used for nat traversal. + AdvertiseAddr string + AdvertisePort int + + // ProtocolVersion is the configured protocol version that we + // will _speak_. This must be between ProtocolVersionMin and + // ProtocolVersionMax. + ProtocolVersion uint8 + + // TCPTimeout is the timeout for establishing a stream connection with + // a remote node for a full state sync, and for stream read and write + // operations. This is a legacy name for backwards compatibility, but + // should really be called StreamTimeout now that we have generalized + // the transport. + TCPTimeout time.Duration + + // IndirectChecks is the number of nodes that will be asked to perform + // an indirect probe of a node in the case a direct probe fails. Memberlist + // waits for an ack from any single indirect node, so increasing this + // number will increase the likelihood that an indirect probe will succeed + // at the expense of bandwidth. + IndirectChecks int + + // RetransmitMult is the multiplier for the number of retransmissions + // that are attempted for messages broadcasted over gossip. The actual + // count of retransmissions is calculated using the formula: + // + // Retransmits = RetransmitMult * log(N+1) + // + // This allows the retransmits to scale properly with cluster size. The + // higher the multiplier, the more likely a failed broadcast is to converge + // at the expense of increased bandwidth. + RetransmitMult int + + // SuspicionMult is the multiplier for determining the time an + // inaccessible node is considered suspect before declaring it dead. + // The actual timeout is calculated using the formula: + // + // SuspicionTimeout = SuspicionMult * log(N+1) * ProbeInterval + // + // This allows the timeout to scale properly with expected propagation + // delay with a larger cluster size. The higher the multiplier, the longer + // an inaccessible node is considered part of the cluster before declaring + // it dead, giving that suspect node more time to refute if it is indeed + // still alive. + SuspicionMult int + + // SuspicionMaxTimeoutMult is the multiplier applied to the + // SuspicionTimeout used as an upper bound on detection time. This max + // timeout is calculated using the formula: + // + // SuspicionMaxTimeout = SuspicionMaxTimeoutMult * SuspicionTimeout + // + // If everything is working properly, confirmations from other nodes will + // accelerate suspicion timers in a manner which will cause the timeout + // to reach the base SuspicionTimeout before that elapses, so this value + // will typically only come into play if a node is experiencing issues + // communicating with other nodes. It should be set to a something fairly + // large so that a node having problems will have a lot of chances to + // recover before falsely declaring other nodes as failed, but short + // enough for a legitimately isolated node to still make progress marking + // nodes failed in a reasonable amount of time. + SuspicionMaxTimeoutMult int + + // PushPullInterval is the interval between complete state syncs. + // Complete state syncs are done with a single node over TCP and are + // quite expensive relative to standard gossiped messages. Setting this + // to zero will disable state push/pull syncs completely. + // + // Setting this interval lower (more frequent) will increase convergence + // speeds across larger clusters at the expense of increased bandwidth + // usage. + PushPullInterval time.Duration + + // ProbeInterval and ProbeTimeout are used to configure probing + // behavior for memberlist. + // + // ProbeInterval is the interval between random node probes. Setting + // this lower (more frequent) will cause the memberlist cluster to detect + // failed nodes more quickly at the expense of increased bandwidth usage. + // + // ProbeTimeout is the timeout to wait for an ack from a probed node + // before assuming it is unhealthy. This should be set to 99-percentile + // of RTT (round-trip time) on your network. + ProbeInterval time.Duration + ProbeTimeout time.Duration + + // DisableTcpPings will turn off the fallback TCP pings that are attempted + // if the direct UDP ping fails. These get pipelined along with the + // indirect UDP pings. + DisableTcpPings bool + + // AwarenessMaxMultiplier will increase the probe interval if the node + // becomes aware that it might be degraded and not meeting the soft real + // time requirements to reliably probe other nodes. + AwarenessMaxMultiplier int + + // GossipInterval and GossipNodes are used to configure the gossip + // behavior of memberlist. + // + // GossipInterval is the interval between sending messages that need + // to be gossiped that haven't been able to piggyback on probing messages. + // If this is set to zero, non-piggyback gossip is disabled. By lowering + // this value (more frequent) gossip messages are propagated across + // the cluster more quickly at the expense of increased bandwidth. + // + // GossipNodes is the number of random nodes to send gossip messages to + // per GossipInterval. Increasing this number causes the gossip messages + // to propagate across the cluster more quickly at the expense of + // increased bandwidth. + // + // GossipToTheDeadTime is the interval after which a node has died that + // we will still try to gossip to it. This gives it a chance to refute. + GossipInterval time.Duration + GossipNodes int + GossipToTheDeadTime time.Duration + + // EnableCompression is used to control message compression. This can + // be used to reduce bandwidth usage at the cost of slightly more CPU + // utilization. This is only available starting at protocol version 1. + EnableCompression bool + + // SecretKey is used to initialize the primary encryption key in a keyring. + // The primary encryption key is the only key used to encrypt messages and + // the first key used while attempting to decrypt messages. Providing a + // value for this primary key will enable message-level encryption and + // verification, and automatically install the key onto the keyring. + // The value should be either 16, 24, or 32 bytes to select AES-128, + // AES-192, or AES-256. + SecretKey []byte + + // The keyring holds all of the encryption keys used internally. It is + // automatically initialized using the SecretKey and SecretKeys values. + Keyring *Keyring + + // Delegate and Events are delegates for receiving and providing + // data to memberlist via callback mechanisms. For Delegate, see + // the Delegate interface. For Events, see the EventDelegate interface. + // + // The DelegateProtocolMin/Max are used to guarantee protocol-compatibility + // for any custom messages that the delegate might do (broadcasts, + // local/remote state, etc.). If you don't set these, then the protocol + // versions will just be zero, and version compliance won't be done. + Delegate Delegate + DelegateProtocolVersion uint8 + DelegateProtocolMin uint8 + DelegateProtocolMax uint8 + Events EventDelegate + Conflict ConflictDelegate + Merge MergeDelegate + Ping PingDelegate + Alive AliveDelegate + + // DNSConfigPath points to the system's DNS config file, usually located + // at /etc/resolv.conf. It can be overridden via config for easier testing. + DNSConfigPath string + + // LogOutput is the writer where logs should be sent. If this is not + // set, logging will go to stderr by default. You cannot specify both LogOutput + // and Logger at the same time. + LogOutput io.Writer + + // Logger is a custom logger which you provide. If Logger is set, it will use + // this for the internal logger. If Logger is not set, it will fall back to the + // behavior for using LogOutput. You cannot specify both LogOutput and Logger + // at the same time. + Logger *log.Logger + + // Size of Memberlist's internal channel which handles UDP messages. The + // size of this determines the size of the queue which Memberlist will keep + // while UDP messages are handled. + HandoffQueueDepth int + + // Maximum number of bytes that memberlist will put in a packet (this + // will be for UDP packets by default with a NetTransport). A safe value + // for this is typically 1400 bytes (which is the default). However, + // depending on your network's MTU (Maximum Transmission Unit) you may + // be able to increase this to get more content into each gossip packet. + // This is a legacy name for backward compatibility but should really be + // called PacketBufferSize now that we have generalized the transport. + UDPBufferSize int +} + +// DefaultLANConfig returns a sane set of configurations for Memberlist. +// It uses the hostname as the node name, and otherwise sets very conservative +// values that are sane for most LAN environments. The default configuration +// errs on the side of caution, choosing values that are optimized +// for higher convergence at the cost of higher bandwidth usage. Regardless, +// these values are a good starting point when getting started with memberlist. +func DefaultLANConfig() *Config { + hostname, _ := os.Hostname() + return &Config{ + Name: hostname, + BindAddr: "0.0.0.0", + BindPort: 7946, + AdvertiseAddr: "", + AdvertisePort: 7946, + ProtocolVersion: ProtocolVersion2Compatible, + TCPTimeout: 10 * time.Second, // Timeout after 10 seconds + IndirectChecks: 3, // Use 3 nodes for the indirect ping + RetransmitMult: 4, // Retransmit a message 4 * log(N+1) nodes + SuspicionMult: 5, // Suspect a node for 5 * log(N+1) * Interval + SuspicionMaxTimeoutMult: 6, // For 10k nodes this will give a max timeout of 120 seconds + PushPullInterval: 30 * time.Second, // Low frequency + ProbeTimeout: 500 * time.Millisecond, // Reasonable RTT time for LAN + ProbeInterval: 1 * time.Second, // Failure check every second + DisableTcpPings: false, // TCP pings are safe, even with mixed versions + AwarenessMaxMultiplier: 8, // Probe interval backs off to 8 seconds + + GossipNodes: 3, // Gossip to 3 nodes + GossipInterval: 200 * time.Millisecond, // Gossip more rapidly + GossipToTheDeadTime: 30 * time.Second, // Same as push/pull + + EnableCompression: true, // Enable compression by default + + SecretKey: nil, + Keyring: nil, + + DNSConfigPath: "/etc/resolv.conf", + + HandoffQueueDepth: 1024, + UDPBufferSize: 1400, + } +} + +// DefaultWANConfig works like DefaultConfig, however it returns a configuration +// that is optimized for most WAN environments. The default configuration is +// still very conservative and errs on the side of caution. +func DefaultWANConfig() *Config { + conf := DefaultLANConfig() + conf.TCPTimeout = 30 * time.Second + conf.SuspicionMult = 6 + conf.PushPullInterval = 60 * time.Second + conf.ProbeTimeout = 3 * time.Second + conf.ProbeInterval = 5 * time.Second + conf.GossipNodes = 4 // Gossip less frequently, but to an additional node + conf.GossipInterval = 500 * time.Millisecond + conf.GossipToTheDeadTime = 60 * time.Second + return conf +} + +// DefaultLocalConfig works like DefaultConfig, however it returns a configuration +// that is optimized for a local loopback environments. The default configuration is +// still very conservative and errs on the side of caution. +func DefaultLocalConfig() *Config { + conf := DefaultLANConfig() + conf.TCPTimeout = time.Second + conf.IndirectChecks = 1 + conf.RetransmitMult = 2 + conf.SuspicionMult = 3 + conf.PushPullInterval = 15 * time.Second + conf.ProbeTimeout = 200 * time.Millisecond + conf.ProbeInterval = time.Second + conf.GossipInterval = 100 * time.Millisecond + conf.GossipToTheDeadTime = 15 * time.Second + return conf +} + +// Returns whether or not encryption is enabled +func (c *Config) EncryptionEnabled() bool { + return c.Keyring != nil && len(c.Keyring.GetKeys()) > 0 +} |