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https://issues.apache.org/jira/browse/PHOENIX-6699?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17533890#comment-17533890
]
ASF GitHub Bot commented on PHOENIX-6699:
-----------------------------------------
stoty commented on code in PR #1431:
URL: https://github.com/apache/phoenix/pull/1431#discussion_r868191956
##########
phoenix-core/src/test/java/org/apache/phoenix/monitoring/MetricUtilTest.java:
##########
@@ -48,4 +52,17 @@ public void testGetMetricsStopWatchWithMetricsFalse() throws
Exception {
LogLevel.OFF, WALL_CLOCK_TIME_MS);
assertFalse(metricsStopWatch.getMetricsEnabled());
}
+
+ @Test
+ //Check that MetricsSystemImpl has a String "prefix" field in the Hadoop
version we test with
+ public void testInternalMetricsField() throws NoSuchFieldException,
+ SecurityException, IllegalArgumentException,
IllegalAccessException {
+ MetricsSystemImpl metrics = (MetricsSystemImpl)
DefaultMetricsSystem.instance();
+ Field prefixField = MetricsSystemImpl.class.getDeclaredField("prefix");
+ prefixField.setAccessible(true);
+ String oldValue = (String)prefixField.get(metrics);
+ prefixField.set(metrics, "dummy");
+ prefixField.set(metrics, oldValue);
+ prefixField.setAccessible(false);
Review Comment:
isDefaultMetricsInitialized() already has a catch-all section to avoid
failing if the API changes, so it cannot really be tested.
> Phoenix metrics overwriting DefaultMetricsSystem in RegionServers
> -----------------------------------------------------------------
>
> Key: PHOENIX-6699
> URL: https://issues.apache.org/jira/browse/PHOENIX-6699
> Project: Phoenix
> Issue Type: Bug
> Components: core
> Affects Versions: 5.2.0
> Reporter: Istvan Toth
> Assignee: Istvan Toth
> Priority: Major
>
> There is a race condition in the Hbase and Phoenix metrics handling.
> Hbase metrics is supposed to run in the daemon processes, while Phoenix
> metrics is supposed to -run on the phoenix client side.- create its own
> DefaultMetrics object on the client side, and add its metrics to the HBase
> DefaultMetrics object on the RS side.
> On an RS both HBase and Phoenix tries to register its metrics implementation
> into DefaultMetricsSystem.
>
> On the happy path, when Phoenix tries to register its metrics on the RS, it
> won't have any effect, because HBase has already registered an active Metrics
> implementation.
> However, JmxCacheBuster stops the Hbase metrics system for ~500ms every five
> seconds, and if Phoenix tries to initialize its metrics in this period, then
> it will succeed in initializing its Metrics object, and will overwrite
> theDefaultMetricsSystem object initialized by HBase.
> This disables the HBase metrics system for the RS process.
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