/// <summary>Checks whether a block is sufficiently replicated for decommissioning.</summary>
/// <remarks>
/// Checks whether a block is sufficiently replicated for decommissioning.
/// Full-strength replication is not always necessary, hence "sufficient".
/// </remarks>
/// <returns>true if sufficient, else false.</returns>
private bool IsSufficientlyReplicated(BlockInfoContiguous block, BlockCollection
bc, NumberReplicas numberReplicas)
{
int numExpected = bc.GetBlockReplication();
int numLive = numberReplicas.LiveReplicas();
if (!blockManager.IsNeededReplication(block, numExpected, numLive))
{
// Block doesn't need replication. Skip.
Log.Trace("Block {} does not need replication.", block);
return(true);
}
// Block is under-replicated
Log.Trace("Block {} numExpected={}, numLive={}", block, numExpected, numLive);
if (numExpected > numLive)
{
if (bc.IsUnderConstruction() && block.Equals(bc.GetLastBlock()))
{
// Can decom a UC block as long as there will still be minReplicas
if (numLive >= blockManager.minReplication)
{
Log.Trace("UC block {} sufficiently-replicated since numLive ({}) " + ">= minR ({})"
, block, numLive, blockManager.minReplication);
return(true);
}
else
{
Log.Trace("UC block {} insufficiently-replicated since numLive " + "({}) < minR ({})"
, block, numLive, blockManager.minReplication);
}
}
else
{
// Can decom a non-UC as long as the default replication is met
if (numLive >= blockManager.defaultReplication)
{
return(true);
}
}
}
return(false);
}
private static void LogBlockReplicationInfo(Block block, BlockCollection bc, DatanodeDescriptor
srcNode, NumberReplicas num, IEnumerable <DatanodeStorageInfo> storages)
{
int curReplicas = num.LiveReplicas();
int curExpectedReplicas = bc.GetBlockReplication();
StringBuilder nodeList = new StringBuilder();
foreach (DatanodeStorageInfo storage in storages)
{
DatanodeDescriptor node = storage.GetDatanodeDescriptor();
nodeList.Append(node);
nodeList.Append(" ");
}
Log.Info("Block: " + block + ", Expected Replicas: " + curExpectedReplicas + ", live replicas: "
+ curReplicas + ", corrupt replicas: " + num.CorruptReplicas() + ", decommissioned replicas: "
+ num.DecommissionedReplicas() + ", excess replicas: " + num.ExcessReplicas() +
", Is Open File: " + bc.IsUnderConstruction() + ", Datanodes having this block: "
+ nodeList + ", Current Datanode: " + srcNode + ", Is current datanode decommissioning: "
+ srcNode.IsDecommissionInProgress());
}
/// <summary>
/// Used while checking if decommission-in-progress datanodes can be marked
/// as decommissioned.
/// </summary>
/// <remarks>
/// Used while checking if decommission-in-progress datanodes can be marked
/// as decommissioned. Combines shared logic of
/// pruneSufficientlyReplicated and handleInsufficientlyReplicated.
/// </remarks>
/// <param name="datanode">Datanode</param>
/// <param name="it">
/// Iterator over the blocks on the
/// datanode
/// </param>
/// <param name="insufficientlyReplicated">
/// Return parameter. If it's not null,
/// will contain the insufficiently
/// replicated-blocks from the list.
/// </param>
/// <param name="pruneSufficientlyReplicated">
/// whether to remove sufficiently
/// replicated blocks from the iterator
/// </param>
/// <returns>
/// true if there are under-replicated blocks in the provided block
/// iterator, else false.
/// </returns>
private void ProcessBlocksForDecomInternal(DatanodeDescriptor datanode, IEnumerator
<BlockInfoContiguous> it, IList <BlockInfoContiguous> insufficientlyReplicated, bool
pruneSufficientlyReplicated)
{
bool firstReplicationLog = true;
int underReplicatedBlocks = 0;
int decommissionOnlyReplicas = 0;
int underReplicatedInOpenFiles = 0;
while (it.HasNext())
{
this.numBlocksChecked++;
BlockInfoContiguous block = it.Next();
// Remove the block from the list if it's no longer in the block map,
// e.g. the containing file has been deleted
if (this._enclosing.blockManager.blocksMap.GetStoredBlock(block) == null)
{
DecommissionManager.Log.Trace("Removing unknown block {}", block);
it.Remove();
continue;
}
BlockCollection bc = this._enclosing.blockManager.blocksMap.GetBlockCollection(block
);
if (bc == null)
{
// Orphan block, will be invalidated eventually. Skip.
continue;
}
NumberReplicas num = this._enclosing.blockManager.CountNodes(block);
int liveReplicas = num.LiveReplicas();
int curReplicas = liveReplicas;
// Schedule under-replicated blocks for replication if not already
// pending
if (this._enclosing.blockManager.IsNeededReplication(block, bc.GetBlockReplication
(), liveReplicas))
{
if (!this._enclosing.blockManager.neededReplications.Contains(block) && this._enclosing
.blockManager.pendingReplications.GetNumReplicas(block) == 0 && this._enclosing.
namesystem.IsPopulatingReplQueues())
{
// Process these blocks only when active NN is out of safe mode.
this._enclosing.blockManager.neededReplications.Add(block, curReplicas, num.DecommissionedReplicas
(), bc.GetBlockReplication());
}
}
// Even if the block is under-replicated,
// it doesn't block decommission if it's sufficiently replicated
if (this._enclosing.IsSufficientlyReplicated(block, bc, num))
{
if (pruneSufficientlyReplicated)
{
it.Remove();
}
continue;
}
// We've found an insufficiently replicated block.
if (insufficientlyReplicated != null)
{
insufficientlyReplicated.AddItem(block);
}
// Log if this is our first time through
if (firstReplicationLog)
{
DecommissionManager.LogBlockReplicationInfo(block, bc, datanode, num, this._enclosing
.blockManager.blocksMap.GetStorages(block));
firstReplicationLog = false;
}
// Update various counts
underReplicatedBlocks++;
if (bc.IsUnderConstruction())
{
underReplicatedInOpenFiles++;
}
if ((curReplicas == 0) && (num.DecommissionedReplicas() > 0))
{
decommissionOnlyReplicas++;
}
}
datanode.decommissioningStatus.Set(underReplicatedBlocks, decommissionOnlyReplicas
, underReplicatedInOpenFiles);
}