I have a standalone instance of HBASE (single instance, on localhost).
After reading a few thousand records using a scanner my thread is stuck
waiting:
"main" prio=10 tid=0x00000000016d4800 nid=0xf3a in Object.wait()
[0x00007fbe96dc3000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Object.java:503)
at org.apache.hadoop.hbase.ipc.HBaseClient.call(HBaseClient.java:757)
- locked <0x00000007e2ba21d0> (a
org.apache.hadoop.hbase.ipc.HBaseClient$Call)
at
org.apache.hadoop.hbase.ipc.HBaseRPC$Invoker.invoke(HBaseRPC.java:257)
at $Proxy4.next(Unknown Source)
at
org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:79)
at
org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:38)
at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getRegionServerWithRetries(HConnectionManager.java:1019)
at
org.apache.hadoop.hbase.client.MetaScanner.metaScan(MetaScanner.java:182)
at
org.apache.hadoop.hbase.client.MetaScanner.metaScan(MetaScanner.java:95)
at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.prefetchRegionCache(HConnectionManager.java:649)
at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegionInMeta(HConnectionManager.java:703)
- locked <0x00000007906dfcf8> (a java.lang.Object)
at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:594)
at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.locateRegion(HConnectionManager.java:559)
at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getRegionLocation(HConnectionManager.java:416)
at
org.apache.hadoop.hbase.client.ServerCallable.instantiateServer(ServerCallable.java:57)
at
org.apache.hadoop.hbase.client.ScannerCallable.instantiateServer(ScannerCallable.java:63)
at
org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.getRegionServerWithRetries(HConnectionManager.java:1018)
at
org.apache.hadoop.hbase.client.HTable$ClientScanner.nextScanner(HTable.java:1104)
at
org.apache.hadoop.hbase.client.HTable$ClientScanner.next(HTable.java:1196)
at
org.apache.hadoop.hbase.client.HTable$ClientScanner$1.hasNext(HTable.java:1256)
at crawler.cache.PageCache.accept(PageCache.java:254)
Concretely, it is stuck on the iterator.next method:
Scan scan = new Scan(Bytes.toBytes(hostnameTarget),
Bytes.toBytes(hostnameTarget + (char) 127));
scan.setMaxVersions(1);
scan.setCaching(4);
ResultScanner resscan = table.getScanner(scan);
Iterator<Result> it = resscan.iterator();
while (it.hasNext()) { // stuck here
Any clues?
