コード例 #1
0
        /// <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);
        }