Vladsz83 commented on a change in pull request #7446: IGNITE-12464 : Service
metrics
URL: https://github.com/apache/ignite/pull/7446#discussion_r401141419
##########
File path:
modules/core/src/main/java/org/apache/ignite/internal/processors/service/IgniteServiceProcessor.java
##########
@@ -1801,4 +1842,178 @@ private boolean enterBusy() {
private void leaveBusy() {
opsLock.readLock().unlock();
}
+
+ /**
+ * Registers metrics to measure durations of service methods.
+ *
+ * @param srvc Service for invocations measurement.
+ * @param srvcName Name of {@code srvc}.
+ */
+ private void registerMetrics(Service srvc, String srvcName) {
+
getInterfaces(srvc.getClass()).stream().map(Class::getMethods).flatMap(Arrays::stream)
+ .filter(mtd -> !isMetricIgnoredFor(mtd.getDeclaringClass()))
+ .forEach(mtd -> {
+ // All metrics for current service.
+ Map<String, MethodHistogramHolder> srvcHistograms =
+ invocationHistograms.computeIfAbsent(srvcName, name -> new
HashMap<>(1));
+
+ // Histograms for this method name.
+ MethodHistogramHolder mtdHistograms =
+ srvcHistograms.computeIfAbsent(mtd.getName(), mdtName ->
new MethodHistogramHolder());
+
+ mtdHistograms.addIfAbsent(mtd, () -> createHistogram(srvcName,
mtd));
+ });
+ }
+
+ /**
+ * Removes metrics for service {@code srvcName}.
+ *
+ * @param srvcName Service name.
+ */
+ private void unregisterMetrics(String srvcName) {
+ ctx.metric().remove(serviceMetricRegistryName(srvcName));
+
+ invocationHistograms.remove(srvcName);
+ }
+
+ /**
+ * Creates histogram for service method. If exist,s considers one or
several argument types has same name but
+ * different package and tries to extend metric name with abbreviation of
java package name.
+ *
+ * @param srvcName Service name.
+ * @param method Method to measure.
+ * @return Histogram of service method timings.
+ */
+ HistogramMetricImpl createHistogram(String srvcName, Method method) {
+ MetricRegistry metricRegistry =
ctx.metric().registry(serviceMetricRegistryName(srvcName));
+
+ HistogramMetricImpl histogram = null;
+
+ // Find/create histogram.
+ for (int i = 0; i <= MAX_ABBREVIATE_NAME_LVL; ++i) {
+ String methodMetricName = methodMetricName(method, i);
+
+ synchronized (metricRegistry) {
+ // If the metric exists skip and try extending metric name in
next cycle.
+ if (metricRegistry.findMetric(methodMetricName) == null) {
+ histogram = metricRegistry.histogram(methodMetricName,
DEFAULT_INVOCATION_BOUNDS,
+ DESCRIPTION_OF_INVOCATION_METRIC);
+
+ break;
+ }
+ }
+ }
+
+ assert histogram != null;
+
+ return histogram;
+ }
+
+ /**
+ * @param method Method for the invocation timings.
+ * @param pkgNameDepth Level of package name abbreviation. See {@link
MetricUtils#abbreviateName(Class, int)}.
+ * @return Metric name for {@code method}.
+ */
+ static String methodMetricName(Method method, int pkgNameDepth) {
+ StringBuilder sb = new StringBuilder();
+
+ sb.append(abbreviateName(method.getReturnType(), pkgNameDepth));
+ sb.append(" ");
+ sb.append(method.getName());
+ sb.append("(");
+ sb.append(Stream.of(method.getParameterTypes()).map(t ->
abbreviateName(t, pkgNameDepth))
+ .collect(Collectors.joining(", ")));
+ sb.append(")");
+
+ return sb.toString();
+ }
+
+ /** @return {@code True} if metrics should not be created for this class
or interface. */
+ private static boolean isMetricIgnoredFor(Class<?> cls){
+ return Object.class.equals(cls) || Service.class.equals(cls) ||
Externalizable.class.equals(cls);
+ }
+
+ /**
+ * Searches histogram for service method.
+ *
+ * @param srvcName Service name.
+ * @param mtd Service method.
+ * @return Histogram for {@code srvcName} and {@code mtd} or {@code null}
if not found.
+ */
+ HistogramMetricImpl histogram(String srvcName, Method mtd) {
Review comment:
As far as I know, concurrent put/get/remove are not atomic but are safe
meaning do not fail or throw an exception. Iteration is a problem here. You can
only get null when a value exist, or a value when it is already removed.
Please, take a look to this simple test. Forks for me. Gives null
periodically, and, I believe, inconsistent values. But no any lock/crash
scenario. What else should we check?
```
@Test
public void testMapConcurrency() throws InterruptedException {
final Map<Integer, Integer> map = new HashMap<>(1);
final Random rnd = new Random();
final int valueCnt = 100000;
final Integer[] holder = new Integer[1];
for(int i=0; i<5; ++i) {
new Thread(() -> {
while (true) {
for (int v = 0; v < valueCnt; ++v)
map.put(v, rnd.nextInt(valueCnt));
System.err.println("Filled");
try {
Thread.sleep(rnd.nextInt(5000));
}
catch (InterruptedException e) {
e.printStackTrace();
}
}
}, "putter_"+i).start();
}
for(int i=0; i<30; ++i) {
new Thread(() -> {
while (true) {
try {
holder[0] = map.get(rnd.nextInt(valueCnt));
Thread.sleep(rnd.nextInt(50));
}
catch (InterruptedException e) {
e.printStackTrace();
}
catch (Exception e) {
e.printStackTrace();
}
}
}, "getter_"+i).start();
}
for(int i=0; i<5; ++i) {
new Thread(() -> {
while (true) {
try {
Thread.sleep(rnd.nextInt(5000));
}
catch (InterruptedException e) {
e.printStackTrace();
}
System.err.println("Clearing");
map.clear();
System.err.println("Cleared");
}
}, "clearer_"+i).start();
}
Thread.sleep(5*60000);
}
```
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