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Type:
Bug
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Resolution: Done
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Priority:
Major - P3
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None
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Affects Version/s: 2.11.2, 2.12.0
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Component/s: Query Operations
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Labels:None
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Environment:java 1.6 and mongodb driver 2.11.2
when I use this command to query the oplog of MongoDB, I got out of memory issue.
cursor = oplogColl.find(query).sort(new BasicDBObject("$natural", 1)).addOption(Bytes.QUERYOPTION_TAILABLE).addOption(Bytes.QUERYOPTION_AWAITDATA);
and through a iterator to get all operation logs.
DBObject data = cursor.next();
Exception description
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOf(Arrays.java:2734)
at java.util.ArrayList.ensureCapacity(ArrayList.java:167)
at java.util.ArrayList.add(ArrayList.java:351)
at com.mongodb.DBApiLayer$Result.init(DBApiLayer.java:369)
at com.mongodb.DBApiLayer$Result._advance(DBApiLayer.java:429)
at com.mongodb.DBApiLayer$Result.hasNext(DBApiLayer.java:396)
at com.mongodb.DBCursor._hasNext(DBCursor.java:464)
at com.mongodb.DBCursor.hasNext(DBCursor.java:484)
at com.patsnap.mongodb.dataload.MongoDbDataLoader.hasNext(MongoDbDataLoader.java:128)
at com.patsnap.mongodb.dataload.MongoDbDataLoader.main(MongoDbDataLoader.java:86)
the reason is that the size type is List<Integer>, It will become big enough if you iterator more data and eventually out of memory
_sizes.add( res.size() );