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8.2.38 DUMP 2350

Code Symbol Kernel Block(s)
data_node_id 2350 operation_filter+ --- ---

Description.  Dumps all operations on a given data node or data nodes, according to the type and other parameters defined by the operation filter or filters specified.

Sample Output.  Dump all operations on data node 2, from API node 5:

ndb_mgm> 2 DUMP 2350 1 5
2011-11-01 13:16:49 [MgmSrvr] INFO     -- Node 2: Starting dump of operations
2011-11-01 13:16:49 [MgmSrvr] INFO     -- Node 2: OP[470]:
Tab: 4 frag: 0 TC: 3 API: 5(0x8035)transid: 0x31c 0x3500500 op: SCAN state: InQueue
2011-11-01 13:16:49 [MgmSrvr] INFO     -- Node 2: End of operation dump

Additional information.  Information about operation filter and operation state values follows.

Operation filter values.  The operation filter (or filters) can take on the following values:

Value Filter
0 table ID
1 API node ID
2 2 transaction IDs, defining a range of transactions
3 transaction coordinator node ID

In each case, the ID of the object specified follows the specifier. See the sample output for examples.

Operation states.  The normal states that may appear in the output from this command are listed here:

  • Transactions:

    • Prepared: The transaction coordinator is idle, waiting for the API to proceed

    • Running: The transaction coordinator is currently preparing operations

    • Committing, Prepare to commit, Commit sent: The transaction coordinator is committing

    • Completing: The transaction coordinator is completing the commit (after commit, some cleanup is needed)

    • Aborting: The transaction coordinator is aborting the transaction

    • Scanning: The transaction coordinator is scanning

  • Scan operations:

    • WaitNextScan: The scan is idle, waiting for API

    • InQueue: The scan has not yet started, but rather is waiting in queue for other scans to complete

  • Primary key operations:

    • In lock queue: The operation is waiting on a lock

    • Running: The operation is being prepared

    • Prepared: The operation is prepared, holding an appropriate lock, and waiting for commit or rollback to complete

Relation to NDB API.  It is possible to match the output of DUMP 2350 to specific threads or Ndb objects. First suppose that you dump all operations on data node 2 from API node 5, using table 4 only, like this:

ndb_mgm> 2 DUMP 2350 1 5 0 4
2011-11-01 13:16:49 [MgmSrvr] INFO     -- Node 2: Starting dump of operations
2011-11-01 13:16:49 [MgmSrvr] INFO     -- Node 2: OP[470]:
Tab: 4 frag: 0 TC: 3 API: 5(0x8035)transid: 0x31c 0x3500500 op: SCAN state: InQueue
2011-11-01 13:16:49 [MgmSrvr] INFO     -- Node 2: End of operation dump

Suppose you are working with an Ndb instance named MyNdb, to which this operation belongs. You can see that this is the case by calling the Ndb object's getReference() method, like this:

  printf("MyNdb.getReference(): 0x%x\n", MyNdb.getReference());

The output from the preceding line of code is:

MyNdb.getReference(): 0x80350005

The high 16 bits of the value shown corresponds to the number in parentheses from the OP line in the DUMP command's output (8035). For more about this method, see Section 2.3.16.1.19, “Ndb::getReference()”.


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