diegosalvi opened a new issue #2243: ConcurrentModificationException while logging a collection URL: https://github.com/apache/bookkeeper/issues/2243 **BUG REPORT** ***Describe the bug*** I got this stackstrace while running BK ``` SLF4J: Failed toString() invocation on an object of type [java.util.HashSet] Reported exception: java.util.ConcurrentModificationException at java.base/java.util.HashMap$HashIterator.nextNode(HashMap.java:1495) at java.base/java.util.HashMap$KeyIterator.next(HashMap.java:1518) at java.base/java.util.AbstractCollection.toString(AbstractCollection.java:456) at org.slf4j.helpers.MessageFormatter.safeObjectAppend(MessageFormatter.java:299) at org.slf4j.helpers.MessageFormatter.deeplyAppendParameter(MessageFormatter.java:271) at org.slf4j.helpers.MessageFormatter.arrayFormat(MessageFormatter.java:233) at org.slf4j.helpers.MessageFormatter.arrayFormat(MessageFormatter.java:173) at org.slf4j.impl.xxxxxxxxxxxxx.error(xxxxxxxxxxxxx.java:236) at org.apache.bookkeeper.client.PendingReadOp.submitCallback(PendingReadOp.java:631) at org.apache.bookkeeper.client.PendingReadOp$LedgerEntryRequest.fail(PendingReadOp.java:170) at org.apache.bookkeeper.client.PendingReadOp$SequenceReadRequest.sendNextRead(PendingReadOp.java:392) at org.apache.bookkeeper.client.PendingReadOp$SequenceReadRequest.logErrorAndReattemptRead(PendingReadOp.java:435) at org.apache.bookkeeper.client.PendingReadOp.readEntryComplete(PendingReadOp.java:581) at org.apache.bookkeeper.proto.BookieClientImpl$2.safeRun(BookieClientImpl.java:369) at org.apache.bookkeeper.common.util.SafeRunnable.run(SafeRunnable.java:36) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) at java.base/java.lang.Thread.run(Thread.java:830) ``` The failing log line is ``` LOG.error("Read of ledger entry failed: L{} E{}-E{}, Sent to {}, " + "Heard from {} : bitset = {}, Error = '{}'. First unread entry is ({}, rc = {})", lh.getId(), startEntryId, endEntryId, sentToHosts, heardFromHosts, heardFromHostsBitSet, BKException.getMessage(code), firstUnread, firstRc); ``` At this time I don't known which collection has been modified while logged (sentToHosts? heardFromHosts?) and I known that the concurrent is generated in slf4j but I think that the problem is in BK: a not concurrent collection has been modified by another thread (perhaps is just wrong the collection logging...). ***To Reproduce*** I'm sorry I don't have any mean to reproduce it ***Expected behavior*** Do not fail on a simple log line
---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
