Monitoring a Amazon Redshift replication scenario requires checking the status of both the Extractor - extracting data from MySQL - and the Applier which retrieves the remote THL information and applies it to Amazon Redshift.

shell> trepctl status
Processing status command...
NAME                     VALUE
----                     -----
appliedLastEventId     : mysql-bin.000006:0000000000002857;-1
appliedLastSeqno       : 15
appliedLatency         : 1.918
autoRecoveryEnabled    : false
autoRecoveryTotal      : 0
channels               : 1
clusterName            : alpha
currentEventId         : mysql-bin.000006:0000000000002857
currentTimeMillis      : 1407336195165
dataServerHost         : redshift1
extensions             : 
host                   : redshift1
latestEpochNumber      : 8
masterConnectUri       : thl://localhost:/
masterListenUri        : thl://redshift1:2112/
maximumStoredSeqNo     : 15
minimumStoredSeqNo     : 0
offlineRequests        : NONE
pendingError           : NONE
pendingErrorCode       : NONE
pendingErrorEventId    : NONE
pendingErrorSeqno      : -1
pendingExceptionMessage: NONE
pipelineSource         : jdbc:mysql:thin://redshift1:3306/tungsten_alpha
relativeLatency        : 35.164
resourcePrecedence     : 99
rmiPort                : 10000
role                   : master
seqnoType              : java.lang.Long
serviceName            : alpha
serviceType            : local
simpleServiceName      : alpha
siteName               : default
sourceId               : redshift1
state                  : ONLINE
timeInStateSeconds     : 34.807
transitioningTo        : 
uptimeSeconds          : 36.493
useSSLConnection       : false
version                : Tungsten Replicator 6.1.25 build 6
Finished status command...

On the Applier, the output of trepctl shows the current sequence number and applier status:

shell> trepctl status
Processing status command...
NAME                     VALUE
----                     -----
appliedLastEventId     : mysql-bin.000006:0000000000002857;-1
appliedLastSeqno       : 15
appliedLatency         : 154.748
autoRecoveryEnabled    : false
autoRecoveryTotal      : 0
channels               : 1
clusterName            : alpha
currentEventId         : NONE
currentTimeMillis      : 1407336316454
dataServerHost         : redshift.us-east-1.redshift.amazonaws.com
extensions             : 
host                   : redshift.us-east-1.redshift.amazonaws.com
latestEpochNumber      : 8
masterConnectUri       : thl://redshift1:2112/
masterListenUri        : null
maximumStoredSeqNo     : 15
minimumStoredSeqNo     : 0
offlineRequests        : NONE
pendingError           : NONE
pendingErrorCode       : NONE
pendingErrorEventId    : NONE
pendingErrorSeqno      : -1
pendingExceptionMessage: NONE
pipelineSource         : thl://redshift1:2112/
relativeLatency        : 156.454
resourcePrecedence     : 99
rmiPort                : 10000
role                   : slave
seqnoType              : java.lang.Long
serviceName            : alpha
serviceType            : local
simpleServiceName      : alpha
siteName               : default
sourceId               : redshift.us-east-1.redshift.amazonaws.com
state                  : ONLINE
timeInStateSeconds     : 2.28
transitioningTo        : 
uptimeSeconds          : 524104.751
useSSLConnection       : false
version                : Tungsten Replicator 6.1.25 build 6
Finished status command...

The appliedLastSeqno should match as normal. Because of the batching of transactions the appliedLatency may be much higher than a normal MySQL to MySQL replication.

The batch loading parameters controlling the batching of data can be tuned and update by studying the output from the trepsvc.log log file. The log will show a line containing the number of rows updated:

INFO  scripting.JavascriptExecutor COUNT: 4

See Section 11.1, “Block Commit” for more information on these parameters.