Baby Python scripts doing powerful work with MQ

I found PyMqi is an interface from Python to MQ. This is really powerful, and I’m am extending it to be even more amazing!

In this blog post, I give examples of what you can do.

• Issue PCF commands and get responses back in words rather than internal codes ( so CHANNEL_NAME instead of 3501)
• Saving the output of DISPLAY commands into files
• Using these files to compare definitions and highlight differences.
• Check these files conform to corporate standards.
• Print out from the command event queue, and the stats event queue etc

I can use some python code to display information via PCF

• # connect to MQ
• qmgr = pymqi.connect( queue_manager,”QMACLIENT”,”127.0.0.1(1414)”)
• # I want to inquire on all SYSTEM.* channels
• prefix = b”SYSTEM.*”
• # This PCF request
• args = {pymqi.CMQCFC.MQCACH_CHANNEL_NAME: prefix}
• pcf = pymqi.PCFExecute(qmgr)
• # go execute it
• response = pcf.MQCMD_INQUIRE_CHANNEL(args)

This is pretty impressive as a C program would take over 1000 lines to do the same!

This comes back with data like

• 3501: b’SYSTEM.AUTO.RECEIVER’,
• 1511: 3,
• 2027: b’2018-08-16 ‘,
• 2028: b’13.32.15′,
• 1502: 50

which is cryptic even for experts because you need to know 3501 is the value of the type of data for “CHANNEL_NAME”.

I have some python code which converts this to..

• ‘CHANNEL_NAME’: ‘SYSTEM.AUTO.RECEIVER’,
• ‘CHANNEL_TYPE’: ‘RECEIVER’,
• ‘ALTERATION_DATE’: ‘2018-08-16’,
• ‘ALTERATION_TIME’: ‘13.32.15’
• ‘BATCH_SIZE’: 50
• …

for which you only need a kinder garden level of MQ knowledge to understand it. It converts 3501 to CHANNEL_NAME, and 3 into RECEIVER

With a few lines of python I can write this data out so each queue is a file on disk in YAML format.

A yaml file for a queue looks like

• Q_NAME: TEMP
• Q_TYPE: LOCAL
• ACCOUNTING_Q: Q_MGR
• ALTERATION_DATE: ‘2019-02-03’
• ALTERATION_TIME: 18.15.52
• BACKOUT_REQ_Q_NAME: ”

Now it gets exciting! (really)

Now it is in YAML, I can write small Python scripts to do clever things. For example

Compare queue definitions

• from ruamel.yaml import YAML
• import sys
• yaml=YAML()
• q1 = sys.argv[1] # get the first queue name
• ignore = [“ALTERATION_DATE”,”ALTERATION_TIME”,
• “CREATION_DATE”,”CREATION_TIME”]
• in1 = open(q1, ‘r’) # open the first queue
• data1 = yaml.load(in1) # and read the contents in
• for i in range(2,len(sys.argv)): # for all of the passed in filenames
• q2=sys.argv[i] # get the name of the file
• in2 = open(q2, ‘r’) # open the file
• data2 = yaml.load(in2) # read it in
• for e in data1: # for each parameter in file 1
• x1 = data1[e] # get the value from file 1
• x2 = data2[e] # get the value from the other file
• if not e in ignore: # some parameters we want to ignore
• if x1 != x2: # if the parameters are different
• print(q1,q2,”:”,e,x1,”/”,x2) # print out the queuenames, keywork and values

From this it prints out the differences

• queues/CP0000.yml queues/CP0001.yml : Q_NAME CP0000 / CP0001
• queues/CP0000.yml queues/CP0001.yml : OPEN_INPUT_COUNT 1 / 0
• queues/CP0000.yml queues/CP0001.yml : MONITORING_Q Q_MGR / HIGH
• queues/CP0000.yml queues/CP0001.yml : OPEN_OUTPUT_COUNT 1 / 0
• queues/CP0000.yml queues/CP0002.yml : Q_NAME CP0000 / CP0002
• queues/CP0000.yml queues/CP0002.yml : OPEN_INPUT_COUNT 1 / 0
• queues/CP0000.yml queues/CP0002.yml : OPEN_OUTPUT_COUNT 1 / 0

I thought pretty impressive for 20 lines of code.

and another script -for checking standards

• from ruamel.yaml import YAML
• import sys
• yaml=YAML()
• q1 = sys.argv[1] # get the queue name
• # define the variables to check
• lessthan = {“MAX_Q_DEPTH”:100}
• ne = {“INHIBIT_PUT”:”PUT_ALLOWED”,”INHIBIT_GET”: “GET_ALLOWED”}
• in1 = open(q1, ‘r’) # open the first queue
• data = yaml.load(in1) # and read the contents in
• # for each element in the LessThan dictionary (MAX_QDEPTH), check with the
• # data read from the file.
• # if the data in the file is “lessthan” the value (100)
• # print print out the name of the queue and the values
• for i in lessthan: # just MAX_Q_DEPTH in this case
• if data1[i] < lessthant[i] : print(q1,i,data[i],”Field in error. It should be less than <“,lessthan[i])
• # if the values are not equal
• for i in ne: # INHIBUT_PUT and #INHIBIT_GET
• if data[i] != ne[i] : print(q1,i,data[i],”field is not equal to “,lt[i])

the output is

queues/CP0000.yml
MAX_Q_DEPTH 5000 Field in error. It should be < 100

Display command events

difference Q_NAME CP0000 CP0000 ALTERATION_DATE 2019-02-07 2019-02-11

difference Q_NAME CP0000 CP0000 ALTERATION_TIME 20.48.24 21.29.23

difference Q_NAME CP0000 CP0000 MAX_Q_DEPTH 4000 2000

With my journey so far – Python seems to be a clear winner in providing the infrastructure for managing queue managers.