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Using Histogram conditionally (only with StoreStats). Updated histogr…
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…am bucket size to 10000
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Chinmay Soman committed Mar 15, 2012
1 parent 667da20 commit 7266799
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Showing 2 changed files with 103 additions and 44 deletions.
104 changes: 76 additions & 28 deletions src/java/voldemort/store/stats/RequestCounter.java
View file
Expand Up @@ -19,25 +19,43 @@ public class RequestCounter {
private final Histogram histogram;
private volatile int q95LatencyMs;
private volatile int q99LatencyMs;
private boolean withHistogram;

/**
* @param durationMS specifies for how long you want to maintain this
* counter (in milliseconds).
*/
public RequestCounter(int durationMS) {
this(durationMS, SystemTime.INSTANCE);
this(durationMS, SystemTime.INSTANCE, false);
}

/**
* @param durationMS specifies for how long you want to maintain this
* counter (in milliseconds). withHistogram indicates that this
* counter should also use a histogram.
*/
public RequestCounter(int durationMS, boolean withHistogram) {
this(durationMS, SystemTime.INSTANCE, withHistogram);
}

/**
* For testing request expiration via an injected time provider
*/
RequestCounter(int durationMS, Time time) {
this(durationMS, time, false);
}

RequestCounter(int durationMS, Time time, boolean withHistogram) {
this.time = time;
this.values = new AtomicReference<Accumulator>(new Accumulator());
this.durationMS = durationMS;
this.histogram = new Histogram(65535, 1);
this.q95LatencyMs = 0;
this.q99LatencyMs = 0;
this.withHistogram = withHistogram;
if(this.withHistogram)
this.histogram = new Histogram(10000, 1);
else
this.histogram = null;
}

public long getCount() {
Expand All @@ -50,8 +68,7 @@ public long getTotalCount() {

public float getThroughput() {
Accumulator oldv = getValidAccumulator();
double elapsed = (time.getMilliseconds() - oldv.startTimeMS)
/ (double) Time.MS_PER_SECOND;
double elapsed = (time.getMilliseconds() - oldv.startTimeMS) / (double) Time.MS_PER_SECOND;
if(elapsed > 0f) {
return (float) (oldv.count / elapsed);
} else {
Expand All @@ -61,8 +78,7 @@ public float getThroughput() {

public float getThroughputInBytes() {
Accumulator oldv = getValidAccumulator();
double elapsed = (time.getMilliseconds() - oldv.startTimeMS)
/ (double) Time.MS_PER_SECOND;
double elapsed = (time.getMilliseconds() - oldv.startTimeMS) / (double) Time.MS_PER_SECOND;
if(elapsed > 0f) {
return (float) (oldv.totalBytes / elapsed);
} else {
Expand Down Expand Up @@ -91,10 +107,12 @@ public long getMaxLatencyInMs() {
}

private void maybeResetHistogram() {
if(!this.withHistogram)
return;
Accumulator accum = values.get();
long now = time.getMilliseconds();
if(now - accum.startTimeMS > durationMS) {
// Reset the histogram
// Reset the histogram
q95LatencyMs = histogram.getQuantile(0.95);
q99LatencyMs = histogram.getQuantile(0.99);
histogram.reset();
Expand Down Expand Up @@ -140,17 +158,24 @@ public void addRequest(long timeNS) {
}

/**
* @see #addRequest(long)
* Detailed request to track additionald data about PUT, GET and GET_ALL
*
* @param numEmptyResponses For GET and GET_ALL, how many keys were no values found
* @see #addRequest(long) Detailed request to track additionald data about
* PUT, GET and GET_ALL
*
* @param numEmptyResponses For GET and GET_ALL, how many keys were no
* values found
* @param bytes Total number of bytes across all versions of values' bytes
* @param getAllAggregatedCount Total number of keys returned for getAll calls
* @param getAllAggregatedCount Total number of keys returned for getAll
* calls
*/
public void addRequest(long timeNS, long numEmptyResponses, long bytes, long getAllAggregatedCount) {
public void addRequest(long timeNS,
long numEmptyResponses,
long bytes,
long getAllAggregatedCount) {
int timeMs = (int) timeNS / (int) Time.NS_PER_MS;
histogram.insert(timeMs);
maybeResetHistogram();
if(this.withHistogram) {
histogram.insert(timeMs);
maybeResetHistogram();
}
for(int i = 0; i < 3; i++) {
Accumulator oldv = getValidAccumulator();
Accumulator newv = new Accumulator(oldv.startTimeMS,
Expand All @@ -168,28 +193,32 @@ public void addRequest(long timeNS, long numEmptyResponses, long bytes, long get
}

/**
* Return the number of requests that have returned returned no value for the requested key. Tracked only for GET.
* Return the number of requests that have returned returned no value for
* the requested key. Tracked only for GET.
*/
public long getNumEmptyResponses() {
return getValidAccumulator().numEmptyResponses;
}

/**
* Return the size of the largest response or request in bytes returned. Tracked only for GET, GET_ALL and PUT.
* Return the size of the largest response or request in bytes returned.
* Tracked only for GET, GET_ALL and PUT.
*/
public long getMaxSizeInBytes() {
return getValidAccumulator().maxBytes;
}

/**
* Return the average size of all the versioned values returned. Tracked only for GET, GET_ALL and PUT.
* Return the average size of all the versioned values returned. Tracked
* only for GET, GET_ALL and PUT.
*/
public double getAverageSizeInBytes() {
return getValidAccumulator().getAverageBytes();
}

/**
* Return the aggregated number of keys returned across all getAll calls, taking into account multiple values returned per call.
* Return the aggregated number of keys returned across all getAll calls,
* taking into account multiple values returned per call.
*/
public long getGetAllAggregatedCount() {
return getValidAccumulator().getAllAggregatedCount;
Expand All @@ -198,32 +227,51 @@ public long getGetAllAggregatedCount() {
public int getQ95LatencyMs() {
return q95LatencyMs;
}

public int getQ99LatencyMs() {
return q99LatencyMs;
}
}

private class Accumulator {

final long startTimeMS;
final long count;
final long totalTimeNS;
final long total;
final long numEmptyResponses; // GET and GET_ALL: number of empty responses that have been returned
final long getAllAggregatedCount; // GET_ALL: a single call to GET_ALL can return multiple k-v pairs. Track total returned.
final long numEmptyResponses; // GET and GET_ALL: number of empty
// responses that have been returned
final long getAllAggregatedCount; // GET_ALL: a single call to GET_ALL
// can return multiple k-v pairs.
// Track total returned.
final long maxLatencyNS;
final long maxBytes; // Maximum single value
final long totalBytes; // Sum of all the values
final long maxBytes; // Maximum single value
final long totalBytes; // Sum of all the values

public Accumulator() {
this(RequestCounter.this.time.getMilliseconds(), 0, 0, 0, 0, 0, 0, 0, 0);
}

public Accumulator newWithTotal() {
return new Accumulator(RequestCounter.this.time.getMilliseconds(), 0, 0, total, 0, 0, 0, 0, 0);
return new Accumulator(RequestCounter.this.time.getMilliseconds(),
0,
0,
total,
0,
0,
0,
0,
0);
}

public Accumulator(long startTimeMS, long count, long totalTimeNS, long total, long numEmptyResponses, long maxLatencyNS, long totalBytes, long maxBytes, long getAllAggregatedCount) {
public Accumulator(long startTimeMS,
long count,
long totalTimeNS,
long total,
long numEmptyResponses,
long maxLatencyNS,
long totalBytes,
long maxBytes,
long getAllAggregatedCount) {
this.startTimeMS = startTimeMS;
this.count = count;
this.totalTimeNS = totalTimeNS;
Expand Down
43 changes: 27 additions & 16 deletions src/java/voldemort/store/stats/StoreStats.java
View file
Expand Up @@ -26,51 +26,62 @@ public StoreStats(StoreStats parent) {
counters = new EnumMap<Tracked, RequestCounter>(Tracked.class);

for(Tracked tracked: Tracked.values()) {
counters.put(tracked, new RequestCounter(300000));
counters.put(tracked, new RequestCounter(300000, true));
}
this.parent = parent;
}

/**
* Record the duration of specified op. For PUT, GET and GET_ALL use specific methods for those ops.
* Record the duration of specified op. For PUT, GET and GET_ALL use
* specific methods for those ops.
*/
public void recordTime(Tracked op, long timeNS) {
recordTime(op, timeNS, 0, 0, 0);
}

/**
* Record the duration of a put operation, along with the size of the values returned.
* Record the duration of a put operation, along with the size of the values
* returned.
*/
public void recordPutTimeAndSize(long timeNS, long size) {
recordTime(Tracked.PUT, timeNS, 0, size, 0);
recordTime(Tracked.PUT, timeNS, 0, size, 0);
}

/**
* Record the duration of a get operation, along with whether or not an empty response (ie no values matched)
* and the size of the values returned.
* Record the duration of a get operation, along with whether or not an
* empty response (ie no values matched) and the size of the values
* returned.
*/
public void recordGetTime(long timeNS, boolean emptyResponse, long totalBytes) {
recordTime(Tracked.GET, timeNS, emptyResponse ? 1 : 0, totalBytes, 0);
}

/**
* Record the duration of a get_all operation, along with how many values were requested, how may were actually
* returned and the size of the values returned.
* Record the duration of a get_all operation, along with how many values
* were requested, how may were actually returned and the size of the values
* returned.
*/
public void recordGetAllTime(long timeNS, int requested, int returned, long totalBytes) {
recordTime(Tracked.GET_ALL, timeNS, requested - returned, totalBytes, requested);
}

/**
* Method to service public recording APIs
*
* @param op Operation being tracked
* @param timeNS Duration of operation
* @param numEmptyResponses GET and GET_ALL: number of empty responses being sent back, ie requested keys for which there were no values
* @param size Total size of response payload, ie sum of lengths of bytes in all versions of values
* @param getAllAggregateRequests Total of key-values requested in aggregatee from get_all operations
*
* @param op Operation being tracked
* @param timeNS Duration of operation
* @param numEmptyResponses GET and GET_ALL: number of empty responses being
* sent back, ie requested keys for which there were no values
* @param size Total size of response payload, ie sum of lengths of bytes in
* all versions of values
* @param getAllAggregateRequests Total of key-values requested in
* aggregatee from get_all operations
*/
private void recordTime(Tracked op, long timeNS, long numEmptyResponses, long size, long getAllAggregateRequests) {
private void recordTime(Tracked op,
long timeNS,
long numEmptyResponses,
long size,
long getAllAggregateRequests) {
counters.get(op).addRequest(timeNS, numEmptyResponses, size, getAllAggregateRequests);
if(parent != null)
parent.recordTime(op, timeNS, numEmptyResponses, size, getAllAggregateRequests);
Expand Down Expand Up @@ -103,7 +114,7 @@ public long getMaxLatencyInMs(Tracked op) {
public long getQ95LatencyInMs(Tracked op) {
return counters.get(op).getQ95LatencyMs();
}

public long getQ99LatencyInMs(Tracked op) {
return counters.get(op).getQ99LatencyMs();
}
Expand Down

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