Vyom Mani Tiwari created RANGER-5542:
----------------------------------------
Summary: ConcurrentModificationException in debug log statements
causes intermittent test failures and suppressed exceptions due to unsafe
string concatenation on shared HashMaps
Key: RANGER-5542
URL: https://issues.apache.org/jira/browse/RANGER-5542
Project: Ranger
Issue Type: Bug
Components: plugins
Affects Versions: 2.8.0, 2.7.0
Reporter: Vyom Mani Tiwari
Assignee: Vyom Mani Tiwari
While investigating intermittent failures of
{{TestRangerBasePluginRaceCondition.testVisibilityOfPolicyEngine()}} (observed
after checking out version 2.8 on macOS), two related
{{ConcurrentModificationException}} occurrences were identified in debug
logging code paths.
Thread-crashing exception in
{{RangerDefaultPolicyResourceMatcher.getMatchType()}} A worker thread crashes
with an uncaught {{ConcurrentModificationException}}
Exception in thread "Thread-12"
java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextNode(HashMap.java:1469)
at java.util.AbstractMap.toString(AbstractMap.java:554)
at
org.apache.ranger.plugin.policyresourcematcher.RangerDefaultPolicyResourceMatcher.getMatchType(RangerDefaultPolicyResourceMatcher.java:601)
at
org.apache.ranger.plugin.policyevaluator.RangerDefaultPolicyEvaluator.evaluate(RangerDefaultPolicyEvaluator.java:228)
{{The root cause is a log statement using string concatenation:}}
LOG.debug("==> getMatchType(" + resource + evalContext + ")");
When {{isDebugEnabled()}} is true, this eagerly calls {{toString()}} on
{{resource}} and {{{}evalContext{}}}, which iterate over live {{HashMap}}
instances. Concurrently, {{setPolicies()}} in another thread modifies these
same HashMaps, triggering the exception. The crashed worker thread never
reports the expected DENY outcome, causing the test to fail intermittently
Suppressed exception in {{RangerAccessRequestImpl.toString()}}
SLF4J: Failed toString() invocation on an object of type
[RangerAccessRequestImpl]
Reported exception:
java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextNode(HashMap.java:1469)
at
org.apache.ranger.plugin.policyengine.RangerAccessRequestImpl.toString(RangerAccessRequestImpl.java:411)
at
org.slf4j.helpers.MessageFormatter.safeObjectAppend(MessageFormatter.java:277)
at
org.apache.ranger.plugin.service.RangerDefaultRequestProcessor.preProcess(RangerDefaultRequestProcessor.java:77)
Currently safe in production because {{isDebugEnabled()}} returns {{false}} in
production environments, preventing these code paths from executing. However,
any developer running tests with debug logging enabled is at risk of
intermittent failures.{{{}{}}}
{{}}
{{}}
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
