Also make snapshot interval configurable

agent/agent.go

@@ -766,6 +766,9 @@ func (a *Agent) consulConfig() (*consul.Config, error) {
 	if a.config.RaftSnapshotThreshold != 0 {
 		base.RaftConfig.SnapshotThreshold = uint64(a.config.RaftSnapshotThreshold)
 	}
+	if a.config.RaftSnapshotInterval != 0 {
+		base.RaftConfig.SnapshotInterval = a.config.RaftSnapshotInterval
+	}
 	if a.config.ACLMasterToken != "" {
 		base.ACLMasterToken = a.config.ACLMasterToken
 	}

agent/config/builder.go

@@ -674,6 +674,7 @@ func (b *Builder) Build() (rt RuntimeConfig, err error) {
 		RPCRateLimit:                rate.Limit(b.float64Val(c.Limits.RPCRate)),
 		RaftProtocol:                b.intVal(c.RaftProtocol),
 		RaftSnapshotThreshold:       b.intVal(c.RaftSnapshotThreshold),
+		RaftSnapshotInterval:        b.durationVal("raft_snapshot_interval", c.RaftSnapshotInterval),
 		ReconnectTimeoutLAN:         b.durationVal("reconnect_timeout", c.ReconnectTimeoutLAN),
 		ReconnectTimeoutWAN:         b.durationVal("reconnect_timeout_wan", c.ReconnectTimeoutWAN),
 		RejoinAfterLeave:            b.boolVal(c.RejoinAfterLeave),

agent/config/config.go

@@ -195,6 +195,7 @@ type Config struct {
 	RPCProtocol                 *int                     `json:"protocol,omitempty" hcl:"protocol" mapstructure:"protocol"`
 	RaftProtocol                *int                     `json:"raft_protocol,omitempty" hcl:"raft_protocol" mapstructure:"raft_protocol"`
 	RaftSnapshotThreshold       *int                     `json:"raft_snapshot_threshold,omitempty" hcl:"raft_snapshot_threshold" mapstructure:"raft_snapshot_threshold"`
+	RaftSnapshotInterval        *string                  `json:"raft_snapshot_interval,omitempty" hcl:"raft_snapshot_interval" mapstructure:"raft_snapshot_interval"`
 	ReconnectTimeoutLAN         *string                  `json:"reconnect_timeout,omitempty" hcl:"reconnect_timeout" mapstructure:"reconnect_timeout"`
 	ReconnectTimeoutWAN         *string                  `json:"reconnect_timeout_wan,omitempty" hcl:"reconnect_timeout_wan" mapstructure:"reconnect_timeout_wan"`
 	RejoinAfterLeave            *bool                    `json:"rejoin_after_leave,omitempty" hcl:"rejoin_after_leave" mapstructure:"rejoin_after_leave"`

agent/config/runtime.go

@@ -905,6 +905,11 @@ type RuntimeConfig struct {
 	// hcl: raft_snapshot_threshold = int
 	RaftSnapshotThreshold int
 
+	// RaftSnapshotInterval sets the interval to use when checking whether to create
+	// a new snapshot. Defaults to 5 seconds.
+	// hcl: raft_snapshot_threshold = int
+	RaftSnapshotInterval time.Duration
+
 	// ReconnectTimeoutLAN specifies the amount of time to wait to reconnect with
 	// another agent before deciding it's permanently gone. This can be used to
 	// control the time it takes to reap failed nodes from the cluster.

agent/config/runtime_test.go

@@ -2422,6 +2422,7 @@ func TestFullConfig(t *testing.T) {
 			"protocol": 30793,
 			"raft_protocol": 19016,
 			"raft_snapshot_threshold": 16384,
+			"raft_snapshot_interval": "30s",
 			"reconnect_timeout": "23739s",
 			"reconnect_timeout_wan": "26694s",
 			"recursors": [ "63.38.39.58", "92.49.18.18" ],
@@ -2854,6 +2855,7 @@ func TestFullConfig(t *testing.T) {
 			protocol = 30793
 			raft_protocol = 19016
 			raft_snapshot_threshold = 16384
+			raft_snapshot_interval = "30s"
 			reconnect_timeout = "23739s"
 			reconnect_timeout_wan = "26694s"
 			recursors = [ "63.38.39.58", "92.49.18.18" ]
@@ -3412,6 +3414,7 @@ func TestFullConfig(t *testing.T) {
 		RPCMaxBurst:               44848,
 		RaftProtocol:              19016,
 		RaftSnapshotThreshold:     16384,
+		RaftSnapshotInterval:      30 * time.Second,
 		ReconnectTimeoutLAN:       23739 * time.Second,
 		ReconnectTimeoutWAN:       26694 * time.Second,
 		RejoinAfterLeave:          true,
@@ -4092,6 +4095,7 @@ func TestSanitize(t *testing.T) {
     "RPCProtocol": 0,
     "RPCRateLimit": 0,
     "RaftProtocol": 0,
+    "RaftSnapshotInterval": "0s",
     "RaftSnapshotThreshold": 0,
     "ReconnectTimeoutLAN": "0s",
     "ReconnectTimeoutWAN": "0s",

agent/consul/config.go

@@ -448,7 +448,7 @@ func DefaultConfig() *Config {
 	// Disable shutdown on removal
 	conf.RaftConfig.ShutdownOnRemove = false
 
-	// Check every 5 seconds to see if there are enough new entries for a snapshot
+	// Check every 5 seconds to see if there are enough new entries for a snapshot, can be overridden
 	conf.RaftConfig.SnapshotInterval = 5 * time.Second
 
 	// Snapshots are created every 8192 entries by default, can be overridden

website/source/docs/agent/options.html.md

@@ -360,7 +360,10 @@ will exit with an error at startup.
   for more details.
 
 * <a name="_raft_snapshot_threshold"></a><a href="#_raft_snapshot_threshold">`-raft-snapshot-threshold`</a> - This
-  control the minimum number of raft commit entries between snapshots that are saved to disk.
+  controls the minimum number of raft commit entries between snapshots that are saved to disk.
+
+* <a name="_raft_snapshot_interval"></a><a href="#_raft_snapshot_interval">`-raft-snapshot-interval`</a> - This
+  controls how often servers check if they need to save a snapshot to disk.
 
 * <a name="_recursor"></a><a href="#_recursor">`-recursor`</a> - Specifies the address of an upstream DNS
   server. This option may be provided multiple times, and is functionally
@@ -939,7 +942,10 @@ Consul will not enable TLS for the HTTP API unless the `https` port has been ass
   [`-raft-protocol` command-line flag](#_raft_protocol).
 
 * <a name="raft_snapshot_threshold"></a><a href="#raft_snapshot_threshold">`raft_snapshot_threshold`</a> Equivalent to the
-    [`-raft-snapshot-threshold` command-line flag](#_raft_snapshot_threshold).
+  [`-raft-snapshot-threshold` command-line flag](#_raft_snapshot_threshold).
+
+* <a name="raft_snapshot_interval"></a><a href="#raft_snapshot_interval">`raft_snapshot_interval`</a> Equivalent to the
+  [`-raft-snapshot-interval` command-line flag](#_raft_snapshot_interval).
 
 * <a name="reap"></a><a href="#reap">`reap`</a> This controls Consul's automatic reaping of child processes,
   which is useful if Consul is running as PID 1 in a Docker container. If this isn't specified, then Consul will