I am trying to run a script or a custom processor to group data by given attributes every hour. Queue size is up to 30-40k on a single run and it might go up to 200k depending on the case.
MergeContent does not fit since there is no limit on min-max counts.
RouteOnAttribute does not fit since there are too many combinations.
Solution 1: Consume all flow files and group by attributes and create the new flow file and push the new one. Not ideal but gave it a try.
While running this when I had 33k flow files on queue waiting.
session.getQueueSize().getObjectCount()
This number is returning 10k all the time even though I increased the queue threshold numbers on output flows.
Solution 2: Better approach is consume one flow file and and filter flow files matching the provided attributes
final List<FlowFile> flowFiles = session.get(file -> {
if (correlationId.equals(Arrays.stream(keys).map(file::getAttribute).collect(Collectors.joining(":"))))
return FlowFileFilter.FlowFileFilterResult.ACCEPT_AND_CONTINUE;
return FlowFileFilter.FlowFileFilterResult.REJECT_AND_CONTINUE;
});
Again with 33k waiting in the queue I was expecting around 200 new grouped flow files but 320 is created. It looks like a similar issue above and does not scan all waiting flow files on filter query.
Problems-Question:
Is there a parameter to change so this getObjectCount can take up to 300k?
Is there a way to filter all waiting flow files again by changing a parameter or by changing the processor?
I tried making default queue threshold 300k on nifi.properties but it didn't help
in nifi.properties there is a parameter that affects batching behavior
nifi.queue.swap.threshold=20000
here is my test flow:
1. GenerateFlowFile with "batch size = 50K"
2. ExecuteGroovyScript with script below
3. LogAttrribute (disabled) - just to have queue after groovy
groovy script:
def ffList = session.get(100000) // get batch with maximum 100K files from incoming queue
if(!ffList)return
def ff = session.create() // create new empty file
ff.batch_size = ffList.size() // set attribute to real batch size
session.remove(ffList) // drop all incoming batch files
REL_SUCCESS << ff // transfer new file to success
with parameters above there are 4 files generated in output:
1. batch_size = 20000
2. batch_size = 10000
3. batch_size = 10000
4. batch_size = 10000
according to documentation:
There is also the notion of "swapping" FlowFiles. This occurs when the number of FlowFiles in a connection queue exceeds the value set in the nifi.queue.swap.threshold property. The FlowFiles with the lowest priority in the connection queue are serialized and written to disk in a "swap file" in batches of 10,000.
This explains that from 50K incoming files - 20K it keeps inmemory and others in swap batched by 10K.
i don't know how increasing of nifi.queue.swap.threshold property will affect your system performance and memory consumption, but i set it to 100K on my local nifi 1.16.3 and it looks good with multiple small files, and first batch increased to 100K by this.
We have been facing an issue where message rate of a xmitq is very slow comparing with what should be a normal performance.
We have many other Qmgrs with bigger MQ flows that don't have the same issue.
Our HUB qmgr connects to business line in the same company HUB qmgr, and even the destination queues on their side being empty the flow is really slow.
At OS and Network level they say nothing can be done. At MQ we have changed the Buffersizes so it matches the OS level and uses the system tcp windows.
Now at MQ level we have the channel SDR setup with BATCHSZ to 100, but seems the receiver is configured with 30.
We noticed that because we see messages flow in batches fof 30 messages. Also not sure if that is related but we see the XMITQ havs always 30 uncommited messages.
Our questiong for advice.
Would increase the BATCHSZ parameter on SDR/RCVR help the perfomance?
Is there any other parameter at MQ level that could help it?
DIS CHS(NAME) ALL
AMQ8417: Display Channel Status details.
CHANNEL(QMGRA.QMGRB.T7) CHLTYPE(SDR)
BATCHES(234) BATCHSZ(30)
BUFSRCVD(235) BUFSSENT(6391)
BYTSRCVD(6996) BYTSSENT(14396692)
CHSTADA(2020-04-16) CHSTATI(14.38.17)
COMPHDR(NONE,NONE) COMPMSG(NONE,NONE)
COMPRATE(0,0) COMPTIME(0,0)
CONNAME(159.50.69.38(48702)) CURLUWID(398F3E5EEA43381C)
CURMSGS(30) CURRENT
CURSEQNO(43488865) EXITTIME(0,0)
HBINT(300) INDOUBT(YES)
JOBNAME(000051FC00000001) LOCLADDR(10.185.8.122(54908))
LONGRTS(999999999) LSTLUWID(398F3E5EE943381C)
LSTMSGDA(2020-04-16) LSTMSGTI(14.49.46)
LSTSEQNO(43488835) MCASTAT(RUNNING)
MONCHL(HIGH) MSGS(6386)
NETTIME(2789746,3087573) NPMSPEED(NORMAL)
RQMNAME(QMGRB) SHORTRTS(10)
SSLCERTI(*******************)
SSLKEYDA( ) SSLKEYTI( )
SSLPEER(*******************)
SSLRKEYS(0) STATUS(RUNNING)
STOPREQ(NO) SUBSTATE(RECEIVE)
XBATCHSZ(23,7) XMITQ(QMGRB.X7)
XQTIME(215757414,214033427) RVERSION(08000008)
RPRODUCT(MQMM)
qm.ini:
Log:
LogPrimaryFiles=10
LogSecondaryFiles=10
LogFilePages=16384
LogType=LINEAR
LogBufferPages=4096
LogPath=/apps/wmq/QMGR/log/QMGR/
LogWriteIntegrity=SingleWrite
Service:
Name=AuthorizationService
EntryPoints=13
TCP:
SvrSndBuffSize=0
SvrRcvBuffSize=0
ServiceComponent:
Service=AuthorizationService
Name=MQSeries.UNIX.auth.service
Module=/opt/mqm75/lib64/amqzfu
ComponentDataSize=0
Channels:
MaxChannels=500
UPDATED: 15:41 GMT
Just to update the information, both sides are now with BATCHSZ 100 and seems slightly.
AMQ8417: Display Channel Status details.
CHANNEL(QMGRA.QMGRB.T7) CHLTYPE(SDR)
BATCHES(403) BATCHSZ(100)
BUFSRCVD(405) BUFSSENT(23525)
BYTSRCVD(11756) BYTSSENT(53751066)
CHSTADA(2020-04-17) CHSTATI(15.13.51)
COMPHDR(NONE,NONE) COMPMSG(NONE,NONE)
COMPRATE(0,0) COMPTIME(0,0)
CONNAME(159.50.69.38(48702)) CURLUWID(6D66985E94343410)
CURMSGS(0) CURRENT
CURSEQNO(44115897) EXITTIME(0,0)
HBINT(300) INDOUBT(NO)
JOBNAME(0000172A00000001) LOCLADDR(10.185.8.122(2223))
LONGRTS(999999999) LSTLUWID(6D66985E93343410)
LSTMSGDA(2020-04-17) LSTMSGTI(15.30.06)
LSTSEQNO(44115897) MCASTAT(RUNNING)
MONCHL(HIGH) MSGS(23505)
NETTIME(101563,480206) NPMSPEED(NORMAL)
RQMNAME(QMGRB) SHORTRTS(10)
SSLCERTI(*************************************)
SSLKEYDA( ) SSLKEYTI( )
SSLPEER(****************************)
SSLRKEYS(0) STATUS(RUNNING)
STOPREQ(NO) SUBSTATE(MQGET)
XBATCHSZ(1,1) XMITQ(QMGRB.X7)
XQTIME(191225,794134) RVERSION(08000008)
RPRODUCT(MQMM)
AMQ8450: Display queue status details.
QUEUE(QMGRB.X7) TYPE(QUEUE)
CURDEPTH(0) IPPROCS(1)
LGETDATE(2020-04-17) LGETTIME(15.30.06)
LPUTDATE(2020-04-17) LPUTTIME(15.30.06)
MEDIALOG(S2488154.LOG) MONQ(LOW)
MSGAGE(0) OPPROCS(9)
QTIME(794134, 191225) UNCOM(NO)
I'll put a few observations in this answer, but based on any further feedback I may add more.
You are running a very old version of the software on the sender side, MQ 7.5 went out of support almost two years ago (April 30 2018). IBM for a cost will provide extended support for an additional three years, so maybe you fall in that group. The 7.5.0.2 maintenance release itself came out in July 11th 2013, so it is almost seven years old at this point. I would strongly suggest you move to a newer version.
Note that MQ v8.0 goes out of support April 30 2020, and IBM just announced a few days ago that MQ v9.0 goes out of support September 30 2021. When you do migrate you should go with either 9.1 which has no announced end of support (they give five years minimum so it could be 2023) or go with the next version of MQ that should be out some time this year.
You mention setting the following:
TCP:
SvrSndBuffSize=0
SvrRcvBuffSize=0
The above setting apply to the SVRCONN end of a client connection. You can see this in the MQ v7.5 Knowledge Center page WebSphere MQ>Configuring>Changing configuration information>Changing queue manager configuration information>TCP, LU62, NETBIOS, and SPX:
SvrSndBuffSize=32768|number
The size in bytes of the TCP/IP send buffer used by the server end of a client-connection
server-connection channel.
SvrRcvBuffSize=32768|number
The size in bytes of the TCP/IP receive buffer used by the server end of a client-connection
server-connection channel.
At IBM MQ v7.5.0.2 APAR IV58073 introduced the concept of setting various buffer settings to a value to 0 which means that it will allow the operating system defaults to be used. Unfortunately like many things in the Knowledge Center it does not look like IBM documented this correctly for 7.5.
You can however review the IBM MQ v8.0 Knowledge Center to get the full picture regarding these settings at the page Configuring>Changing configuration information>Changing queue manager configuration information>TCP, LU62, and NETBIOS, specifically you would want to set these two settings to have any impact on your Sender Channel:
SndBuffSize=number| 0
The size in bytes of the TCP/IP send buffer used by the sending end of
channels. This stanza value can be overridden by a stanza more
specific to the channel type, for example RcvSndBuffSize. If the
value is set as zero, the operating system defaults are used. If no
value is set, then the IBM MQ default, 32768, is used.
RcvSndBuffSize=number| 0
The size in bytes of the TCP/IP send buffer used by the sender end of
a receiver channel. If the value is set as zero, the operating system
defaults are used. If no value is set, then the IBM MQ default, 32768,
is used.
Starting at IBM MQ v8.0 any newly created queue manager will have all of the following in the qm.ini:
TCP:
SndBuffSize=0
RcvBuffSize=0
RcvSndBuffSize=0
RcvRcvBuffSize=0
ClntSndBuffSize=0
ClntRcvBuffSize=0
SvrSndBuffSize=0
SvrRcvBuffSize=0
However, any queue manager that is upgraded will not by default get those settings, meaning if those are not present they will not be added, if they are present they will remain the same. If the setting is not present then as it says above "the IBM MQ default, 32768, is used."
I had extensive discussions with IBM support on this topic and came to the conclusion that they did not see any reason to not set it to 0, they only saw benefit in doing so, but with an abundance of caution they do not change it to 0 for you.
I would recommend you add all of those to your qm.ini, but at minimum add the two I highlighted above.
These are good setting to implement but may not solve your problem if nothing changed recently on either end. If however something did change, for example a network difference, or MQ was upgraded to 8.0.0.8 on the remote side, then this setting just might solve your problem.
In the channel status output two values are interesting:
NETTIME(2789746,3087573)
XQTIME(215757414,214033427)
NETTIME means that based on recent activity it took 2.7 seconds to receive a response from the RCVR channel, over a longer period of time it took 3.1 seconds to receive a response from the RCVR channel. Can you compare this to a TCP ping from the sender channel server to the receive channel server, 2.7 seconds for a response over the network seems excessive. In the presentation Keeping MQ Channels Up and Running given at Capitalware's MQ Technical Conference v2.0.1.4, Paul Clarke who used to work for IBM states "NETTIME only measures network time, and does not include
the MQCMIT for example".
XQTIME means that based on recent activity and over a longer period of time it took ~215 seconds for a message on the XMITQ to be picked up by the SDR channel to be sent.
See below for how IBM documents these:
NETTIME
Amount of time, displayed in microseconds, to send a request to the remote end of the channel and receive a response. This time only measures the network time for such an operation. Two values are displayed:
A value based on recent activity over a short period.
A value based on activity over a longer period.
XQTIME
The time, in microseconds, that messages remained on the transmission queue before being retrieved. The time is measured from when the message is put onto the transmission queue until it is retrieved to be sent on the channel and, therefore, includes any interval caused by a delay in the putting application.
Two values are displayed:
A value based on recent activity over a short period.
A value based on activity over a longer period.
Information on the BATCHSZ channel parameter can be found in the IBM MQ v8.0 Knowledge Center page Reference>Configuration reference>Channel attributes>Channel attributes in alphabetical order>Batch size (BATCHSZ). I have quoted it and highlighted a few areas in bold.
This attribute is the maximum number of messages to be sent before a sync point is taken.
The batch size does not affect the way the channel transfers messages; messages are always transferred individually, but are committed or backed out as a batch.
To improve performance, you can set a batch size to define the maximum number of messages to be transferred between two sync points. The batch size to be used is negotiated when a channel starts, and the lower of the two channel definitions is taken. On some implementations, the batch size is calculated from the lowest of the two channel definitions and the two queue manager MAXUMSGS values. The actual size of a batch can be less; for example, a batch completes when there are no messages left on the transmission queue or the batch interval expires.
A large value for the batch size increases throughput, but recovery times are increased because there are more messages to back out and send again. The default BATCHSZ is 50, and you are advised to try that value first. You might choose a lower value for BATCHSZ if your communications are unreliable, making the need to recover more likely.
This attribute is valid for channel types of:
Sender
Server
Receiver
Requester
Cluster sender
Cluster receiver
Follow up questions:
Are the messages that are PUT to this XMITQ persistent?
Answer: Yes, in our PROD env all messages are pesistent.
Have you had a recent increase in volume going to this XMITQ?
Answer: No, we use a monitoring tools, we extracted a report that show very similar message rate during the period. The same rate over the last 2 weeks.
Do the putting applications set MQPMO_SYNCPOINT and then commit after 1 or more messages are PUT to the queue?
Answer: I will check with the application team.
A couple of things..
You have XBATCHSZ(1,1) so your recent batch size is 1 message per batch.
Total messages 23505 batches 403, so an average of 58 messages per batch. If your recent batch size is 1, then you must have had some larger (100?) batch sizes
XQTIME 191225 is number of microseconds messages were on the xmit queue before being sent. This is 0.1 second!
Nettime 101563 microseconds. This is a long time ( 0.1 seconds) 10,000 would be a good value. Compare this with a "TCP PING"
BUFSSENT 23525 is similar to number of messages - so message size is typically under 32K. Bytessent. messages gives 2286 so small messages.
Things to check
The queue at the remote end. Has it filled up? This would cause the sender queue to get more messages
The nettime seems very long. Compare this with TCP Ping. Nettime can include slow IO at the remote end - or a queue full at the remote end
XQTIME is high. This could be caused by sending applications not committing, or slow disk IO
I wrote "Why is my xmit queue filling up" in this blog
*Search for the title
have a read.
Capture these metrics over a day and see if they are typical
regards
Colin Paice
We are testing the capacity of a Mail relay based on RHEL 7.6.
We are observing issues when sending an important number of msgs (e.g.: ~1000 msgs in 60 seconds).
While we have sent all the msgs and the recipient has received all the msgs, logs are missing in the /var/log/maillog_rfc5424.
We have the following message in the /var/log/messages:
rsyslogd: imjournal: XYZ messages lost due to rate-limiting
We adapted the /etc/rsyslog.conf with the following settings but without effect:
$SystemLogRateLimitInterval 0 # turn off rate limit
$SystemLogRateLimitBurst 0 # turn rate limit off
Any ideas ?
The error is from imjournal, but your configuration settings are for imuxsock.
According to the rsyslog configuration page you need to set
$imjournalRatelimitInterval 0
$imjournalRatelimitBurst 0
Note that for very high message rates you might like to change to imuxsock, as it says:
this module may be notably slower than when using imuxsock. The journal provides imuxsock with a copy of all “classical” syslog messages, however, it does not provide structured data. Only if that structured data is needed, imjournal must be used. Otherwise, imjournal may simply be replaced by imuxsock, and we highly suggest doing so.
I'm new to Flume and I was exploring options to roll over my HDFS files on hourly basis using Flume.
In my project Apache Flume will read the messages from Rabbit MQ and it will write it to HDFS.
hdfs.rollInterval - It closes the file based on the time interval when it got opened.
New file will be created only when Flume reads a message after the file got closed. This option is not solving our problem.
hdfs.path = /%y/%m/%d/%H - This option is working fine and it creates folder on hourly basis. But the problem is new folder will be created only when new message comes.
For example: Messages are coming till 11.59, the file will be in open state. Then the messages stop coming till 12.30. But, the file will still be in open state. After 12.30 new message comes. Then because of hdfs.path configuration, previous file will be closed and new file will be created in new folder.
Previous file cannot be used for computation till it is closed.
We need an option of closing the opened files on hourly basis perfectly. I'm wondering if there any options in flume for doing that.
hdfs.rollInterval is described as
Number of seconds to wait before rolling current file
So this line should cause the files to allocate for an hour at a time
hdfs.rollInterval = 3600
And I would additionally ignore file size and event count, so add these as well
hdfs.rollSize = 0
hdfs.rollCount = 0
hdfs.idleTimeout
Timeout after which inactive files get closed (0 = disable automatic closing of idle files)
For example, you can set this property to 180. The file will be opened
I am trying to write the flume events in Amaozn S3.The events written in S3 is in compressed format. My Flume configuration is given below. I am facing a data loss. Based on the configuration given below, if I publish 20000 events, I receive only 1000 events and all other data is lost. But When I disable the rollcount, rollSize and rollInterval configurations, all the events are received but there are 2000 small files created. Is there any wrong in my configuration settings? Should I add any other configurations?
injector.sinks.s3_3store.type = hdfs
injector.sinks.s3_3store.channel = disk_backed4
injector.sinks.s3_3store.hdfs.fileType = CompressedStream
injector.sinks.s3_3store.hdfs.codeC = gzip
injector.sinks.s3_3store.hdfs.serializer = TEXT
injector.sinks.s3_3store.hdfs.path = s3n://CID:SecretKey#bucketName/dth=%Y-%m-%d-%H
injector.sinks.s3_1store.hdfs.filePrefix = events-%{receiver}
# Roll when files reach 256M or after 10m, whichever comes first
injector.sinks.s3_3store.hdfs.rollCount = 0
injector.sinks.s3_3store.hdfs.idleTimeout = 600
injector.sinks.s3_3store.hdfs.rollSize = 268435456
#injector.sinks.s3_3store.hdfs.rollInterval = 3600
# Flush data to buckets every 1k events
injector.sinks.s3_3store.hdfs.batchSize = 10000
For starters: if you disable your setting for rollCount, rollSize and so on, flume will revert to defaults, hence the small files you receive, those are the default.
The relevant aspect is this:
injector.sinks.s3_3store.hdfs.batchSize = 10000
it basically tells your sink to collect 10.000 events before flushing. If you reduce that amount, you'll get smaller files too, because S3 in contrast to regular HDFS doesn't support file appends. Once you flush, the files will be closed and a new file will be created.
Try to determine which amount of events your sink will receive within a short time frame of a couple of minutes or so and set that value as you batch size.