update mongostat from github.com/mongodb/mongo-tools

closes #323

plugins/mongodb/mongostat.go

@@ -208,10 +208,11 @@ type LockStats struct {
 	TimeLockedMicros    ReadWriteLockTimes `bson:"timeLockedMicros"`
 	TimeAcquiringMicros ReadWriteLockTimes `bson:"timeAcquiringMicros"`
 
-	// AcquireCount is a new field of the lock stats only populated on 3.0 or newer.
+	// AcquireCount and AcquireWaitCount are new fields of the lock stats only populated on 3.0 or newer.
 	// Typed as a pointer so that if it is nil, mongostat can assume the field is not populated
 	// with real namespace data.
-	AcquireCount *ReadWriteLockTimes `bson:"acquireCount,omitempty"`
+	AcquireCount     *ReadWriteLockTimes `bson:"acquireCount,omitempty"`
+	AcquireWaitCount *ReadWriteLockTimes `bson:"acquireWaitCount,omitempty"`
 }
 
 // ExtraInfo stores additional platform specific information.
@@ -246,6 +247,8 @@ var StatHeaders = []StatHeader{
 	{"res", Always},
 	{"non-mapped", MMAPOnly | AllOnly},
 	{"faults", MMAPOnly},
+	{"lr|lw %", MMAPOnly | AllOnly},
+	{"lrt|lwt", MMAPOnly | AllOnly},
 	{"    locked db", Locks},
 	{"qr|qw", Always},
 	{"ar|aw", Always},
@@ -276,6 +279,13 @@ func percentageInt64(value, outOf int64) float64 {
 	return 100 * (float64(value) / float64(outOf))
 }
 
+func averageInt64(value, outOf int64) int64 {
+	if value == 0 || outOf == 0 {
+		return 0
+	}
+	return value / outOf
+}
+
 func (slice lockUsages) Len() int {
 	return len(slice)
 }
@@ -288,6 +298,14 @@ func (slice lockUsages) Swap(i, j int) {
 	slice[i], slice[j] = slice[j], slice[i]
 }
 
+// CollectionLockStatus stores a collection's lock statistics.
+type CollectionLockStatus struct {
+	ReadAcquireWaitsPercentage  float64
+	WriteAcquireWaitsPercentage float64
+	ReadAcquireTimeMicros       int64
+	WriteAcquireTimeMicros      int64
+}
+
 // LockStatus stores a database's lock statistics.
 type LockStatus struct {
 	DBName     string
@@ -314,6 +332,9 @@ type StatLine struct {
 	// Opcounter fields
 	Insert, Query, Update, Delete, GetMore, Command int64
 
+	// Collection locks (3.0 mmap only)
+	CollectionLocks *CollectionLockStatus
+
 	// Cache utilization (wiredtiger only)
 	CacheDirtyPercent float64
 	CacheUsedPercent  float64
@@ -467,6 +488,23 @@ func NewStatLine(oldStat, newStat ServerStatus, key string, all bool, sampleSecs
 			// This appears to be a 3.0+ server so the data in these fields do *not* refer to
 			// actual namespaces and thus we can't compute lock %.
 			returnVal.HighestLocked = nil
+
+			// Check if it's a 3.0+ MMAP server so we can still compute collection locks
+			collectionCheck, hasCollection := oldStat.Locks["Collection"]
+			if hasCollection && collectionCheck.AcquireWaitCount != nil {
+				readWaitCountDiff := newStat.Locks["Collection"].AcquireWaitCount.Read - oldStat.Locks["Collection"].AcquireWaitCount.Read
+				readTotalCountDiff := newStat.Locks["Collection"].AcquireCount.Read - oldStat.Locks["Collection"].AcquireCount.Read
+				writeWaitCountDiff := newStat.Locks["Collection"].AcquireWaitCount.Write - oldStat.Locks["Collection"].AcquireWaitCount.Write
+				writeTotalCountDiff := newStat.Locks["Collection"].AcquireCount.Write - oldStat.Locks["Collection"].AcquireCount.Write
+				readAcquireTimeDiff := newStat.Locks["Collection"].TimeAcquiringMicros.Read - oldStat.Locks["Collection"].TimeAcquiringMicros.Read
+				writeAcquireTimeDiff := newStat.Locks["Collection"].TimeAcquiringMicros.Write - oldStat.Locks["Collection"].TimeAcquiringMicros.Write
+				returnVal.CollectionLocks = &CollectionLockStatus{
+					ReadAcquireWaitsPercentage:  percentageInt64(readWaitCountDiff, readTotalCountDiff),
+					WriteAcquireWaitsPercentage: percentageInt64(writeWaitCountDiff, writeTotalCountDiff),
+					ReadAcquireTimeMicros:       averageInt64(readAcquireTimeDiff, readWaitCountDiff),
+					WriteAcquireTimeMicros:      averageInt64(writeAcquireTimeDiff, writeWaitCountDiff),
+				}
+			}
 		} else {
 			prevLocks := parseLocks(oldStat)
 			curLocks := parseLocks(newStat)