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The [[Model 204]] DBMS can run in a number of modes, [[Model 204 Batch | Batch]] and '''Online''' being the primary two.  In both cases Model 204 appears as a single address space on the operator console under z/OS and VSE, or as a virtual machine under VM.
The <var class="product">[[Model 204]]</var> DBMS can run in a number of modes, [[Using HLI and batch configurations#BATCH204|BATCH204]] and '''Online''' being the primary two.  In both cases <var class="product">Model 204</var> appears as a single address space on the operator console under z/OS and VSE, or as a virtual machine under VM.


In the early history of Model 204, this distinction resulted in the somewhat odd use of the word ''Online'' as a noun. Specifically, as a shorthand for referring to the address space, region, or virtual machine running Model 204 in Online mode, people would just refer to an &ldquo;Online&rdquo;. For example, someone might say, &ldquo;The production Online is running a bit slow, today&rdquo;, or &rdquo;Can you log into the test Online and look at something for me?&rdquo; This shorthand is convenient and is ubiquitous in the Model 204 community, so is used heavily in much of the Model 204 documentation and in many of the pages in the Sirius Wiki.
In the early history of <var class="product">Model 204</var>, this distinction resulted in the somewhat odd use of the word <code>Online</code> as a noun. Specifically, as a shorthand for referring to the address space, region, or virtual machine running <var class="product">Model 204</var> in Online mode, people would just refer to an "Online". For example, someone might say, "The production Online is running a bit slow, today," or "Can you log into the test Online and look at something for me?" This shorthand is convenient, and it is ubiquitous in the <var class="product">Model 204</var> community, so it is used heavily in much of the <var class="product">Model 204</var> documentation.


=Overview=
==Overview==
In Batch mode, <var class="product">Model 204</var> is defined with no input/output devices (aka '''IODEV threads''', or just '''IODEVs'''), and runs as a single batch user, executing all the commands and programs in the '''CCAIN DD''', until the command stream is exhausted, after which the job stops.


In Batch mode, Model 204 is defined with no input/output devices (aka '''IODEV threads''', or just '''IODEVs'''), and runs as a single batch user, executing all the commands and programs in the '''CCAIN DD''', until the command stream is exhausted, after which the job stops.
In Online mode, <var class="product">Model 204</var> is defined as a single "batch" user (aka "User 0") with a number of online users.  Here too, the job runs, executing all commands in '''CCAIN''' until the job completes.  The purpose of an Online job, however, is to provide a DBMS environment for users to log into and work with the data, so Online jobs typically run for very long periods of time.  To make this possible, an Online CCAIN stream contains a <var>HALT</var> command near the end of the stream, which specifies an operator command that may be used to stop the job.  Execution of the <var class="product">Model 204</var> Online waits at this command until the operator issues the "stop" command, which is usually <var>EOD</var> for End Of Day, or <var>EOJ</var> for End Of Job.  System Managers may also issue these commands from a terminal session inside <var class="product">Model 204</var>.


In Online mode, Model 204 is defined as a single "batch" user (aka "USER 0") with a number of online users.  Here too, the job runs, executing all commands in '''CCAIN''' until the job completes.  The purpose of an Online job, however, is to provide a DBMS environment for users to log into and work with the data, so Online jobs typically run for very long periods of time.  To make this possible, an Online CCAIN stream contains a '''HALT''' command near the end of the stream, which specifies an operator command that may be used to stop the job.  Execution of the Model 204 Online waits at this command until the operator issues the "stop" command, which is usually '''EOD''' for End Of Day, or '''EOJ''' for End Of Job.  System Managers may also issue these commands from a terminal session inside Model 204.
If the correct procedures for stopping an Online are not followed, severe damage can be done to database files, and loss of data can occur.  Usually Online jobs are configured to run a recovery step before making the online available for user sessions, and <var class="product">Model 204</var> recovery will automatically repair a large number of problems resulting from abnormal termination.


If the correct procedures for stopping an Online are not followed, severe damage can be done to database files, and loss of data can occurUsually Online jobs are configured to run a recovery step before making the online available for user sessions, and Model 204 recovery will automatically repair a large number of problems resulting from abnormal termination.
It is important to know that, because <var class="product">Model 204</var> hosts its own terminal services, hundreds, or even thousands, of users can be logged into a <var class="product">Model 204</var> Online simultaneously.  On the console, the operator will see only a very large job consuming significant resources.  Without proper training, an operator may see this job as a performance anomaly, and might cancel it, inconveniencing a large number of users and interrupting the day's flow of workThe details of what is happening inside an Online can only be viewed by users with terminal sessions inside the job, via various system-monitoring commands like <var>LOGWHO</var> and variations on the <var>MONITOR</var> command.  Highly detailed views of performance characteristics can be analyzed in the <var class="product">Model 204</var> journal via [[SirScan]] and with a system, file and user monitoring tool like [[SirMon]].


It is important to know that, because Model 204 hosts its own terminal services, hundreds, or even thousands, of users can be logged into a Model 204 Online simultaneously.  On the console, the operator will see only a very large job consuming significant resources.  Without proper training, an operator may see this job as a performance anomaly, and might cancel it, inconveniencing a large number of users and interrupting the day's flow of work.  The details of what is happening inside an Online can only be viewed by users with terminal sessions inside the job, via various system-monitoring commands like '''LOGWHO''' and variations on the '''MONITOR''' command.  Highly detailed views of performance characteristics can be analyzed in the Model 204 journal via [[SirScan]] and with a system, file and user monitoring tool like [[SirMon]].
==Online job specification==
 
This is how a <var class="product">Model 204</var> Online job is typically built:
=Online Job Specification=
 
This is how a Model 204 online job is typically built:


  //M204ONLN JOB CLASS=A,MSGCLASS=A,NOTIFY=LEN
  //M204ONLN JOB CLASS=A,MSGCLASS=A,NOTIFY=LEN
Line 65: Line 63:
  EOJ
  EOJ


Note the positional continuation-line markers for the first entries in CCAIN.  These are required so that all the parameters needed to define the Online environment are read. Also note the first parameter '''NUSERS''' matches the number of '''IODEVs''' plus 1 (for the USER0 user).  It is the presence of NUSERS greater than 1, and the different types of input/output devices that differentiate a Model 204 Online job from a Batch job.
Note the positional continuation-line markers for the first entries in CCAIN.  These are required so that all the parameters needed to define the Online environment are read. Also note that the first parameter, <var>NUSERS</var>, matches the number of '''IODEVs''' plus 1 (for the User 0 user).  It is the presence of <var>NUSERS</var> greater than 1, and the different types of input/output devices, that differentiate a <var class="product">Model 204</var> Online job from a Batch job.


=Other Model 204 run modes=
==Other Model 204 run modes==
The other modes of configuring and running <var class="product">Model 204</var> are called [[Using HLI and batch configurations#IFAM1|IFAM1]], [[Using HLI and batch configurations#IFAM2|IFAM2]], [[Using HLI and batch configurations#IFAM4 for z/OS|IFAM4]], and [[BATCH2 (TCP/IP)|BATCH2]].


The other modes Model 204 can run in are called '''IFAM1''', '''IFAM2''', '''IFAM4''' and '''[[BATCH2 (TC/IP)|BATCH2]]'''.  All these ways of configuring and running Model 204, and sample code for configuring each, are documented in the ''Model 204 System Manager's Guide''.
[[Category:Model 204 operational issues]]

Latest revision as of 17:59, 23 April 2018

The Model 204 DBMS can run in a number of modes, BATCH204 and Online being the primary two. In both cases Model 204 appears as a single address space on the operator console under z/OS and VSE, or as a virtual machine under VM.

In the early history of Model 204, this distinction resulted in the somewhat odd use of the word Online as a noun. Specifically, as a shorthand for referring to the address space, region, or virtual machine running Model 204 in Online mode, people would just refer to an "Online". For example, someone might say, "The production Online is running a bit slow, today," or "Can you log into the test Online and look at something for me?" This shorthand is convenient, and it is ubiquitous in the Model 204 community, so it is used heavily in much of the Model 204 documentation.

Overview

In Batch mode, Model 204 is defined with no input/output devices (aka IODEV threads, or just IODEVs), and runs as a single batch user, executing all the commands and programs in the CCAIN DD, until the command stream is exhausted, after which the job stops.

In Online mode, Model 204 is defined as a single "batch" user (aka "User 0") with a number of online users. Here too, the job runs, executing all commands in CCAIN until the job completes. The purpose of an Online job, however, is to provide a DBMS environment for users to log into and work with the data, so Online jobs typically run for very long periods of time. To make this possible, an Online CCAIN stream contains a HALT command near the end of the stream, which specifies an operator command that may be used to stop the job. Execution of the Model 204 Online waits at this command until the operator issues the "stop" command, which is usually EOD for End Of Day, or EOJ for End Of Job. System Managers may also issue these commands from a terminal session inside Model 204.

If the correct procedures for stopping an Online are not followed, severe damage can be done to database files, and loss of data can occur. Usually Online jobs are configured to run a recovery step before making the online available for user sessions, and Model 204 recovery will automatically repair a large number of problems resulting from abnormal termination.

It is important to know that, because Model 204 hosts its own terminal services, hundreds, or even thousands, of users can be logged into a Model 204 Online simultaneously. On the console, the operator will see only a very large job consuming significant resources. Without proper training, an operator may see this job as a performance anomaly, and might cancel it, inconveniencing a large number of users and interrupting the day's flow of work. The details of what is happening inside an Online can only be viewed by users with terminal sessions inside the job, via various system-monitoring commands like LOGWHO and variations on the MONITOR command. Highly detailed views of performance characteristics can be analyzed in the Model 204 journal via SirScan and with a system, file and user monitoring tool like SirMon.

Online job specification

This is how a Model 204 Online job is typically built:

//M204ONLN JOB CLASS=A,MSGCLASS=A,NOTIFY=LEN
//RUN EXEC PGM=ONLINE,REGION=8M,
// TIME=1440,PARM=('SYSOPT=149,LIBUFF=1024,LOBUFF=3000')
//STEPLIB DD DSN=M204.RLSE.LOADLIB,DISP=SHR
//CCAJRNL DD DSN=M204.JOURNAL,DISP=SHR
//CHKPOINT DD DSN=M204.CHKPOINT,DISP=SHR
//CCATEMP DD UNIT=3390,SPACE=(TRK,90),
// DISP=(NEW,DELETE)
//CCASNAP DD SYSOUT=A
//SYSMDUMP DD SYSOUT=A
//SYSUDUMP DD SYSOUT=A
//CCAAUDIT DD SYSOUT=A
//CCASTAT DD DSN=M204.CCASTAT,DISP=SHR
//CCAGRP DD DSN=M204.CCAGRP,DISP=SHR
//CLIENTS DD DSN=M204.FILE.CLIENTS,DISP=SHR
//VEHICLES DD DSN=M204.FILE.VEHICLES,DISP=SHR
//CLAIMS89 DD DSN=M204.FILE.CLAIMS89,DISP=SHR
//CLAIMS90 DD DSN=M204.FILE.CLAIMS90,DISP=SHR
//CCASERVR DD UNIT=3380,DISP=(NEW,DELETE),
// SPACE=(CYL,5,,CONTIG)
//CCAPRINT DD SYSOUT=A
//CCAIN DD *
NUSERS=9,NSERVS=2,MINBUF=18,MAXBUF=1000,                               X
TERMBUF=5,NFILES=4,NDCBS=4,NDIR=4,SPCORE=50000,                        X
IFAMBS=4000,LRETBL=800,VTAMNAME=M204,CRFSCHNL=M204FULL,                X
CRIOCHNL=M204PROD,IFAMCHNL=IFAMPROD,                                   X
RCVOPT=9,CPMAX=1,CPTIME=30,CPTO=5,CPTQ=5,                              X
LFSCB=7000,LGTBL=500,LSTBL=3000,LVTBL=200,                             X
LOUTPB=3000,NBKPG=5,OUTCCC=80,SERVSIZE=72456
IODEV=7,NOTERM=3,POLLNO=1,SERVSIZE=72456
IODEV=7,POLLNO=2
IODEV=7,POLLNO=3
IODEV=29,NOTERM=2,POLLNO=1
IODEV=29,POLLNO=2
IODEV=11,NOTERM=2,POLLNO=1
IODEV=11,POLLNO=2
IODEV=23
HALT 27,MODEL 204 IS UP AND RUNNING,3,EOD
EOD
*SLEEP 300
BROADCAST URGENT 1***SYSTEM GOES DOWN IN 5 MINUTES
*SLEEP 300
HALT 24,WAIT FOR USERS TO LOGOUT,3,EOJ
CHECKPOINT
BUMP ALL
*SLEEP 300
EOJ

Note the positional continuation-line markers for the first entries in CCAIN. These are required so that all the parameters needed to define the Online environment are read. Also note that the first parameter, NUSERS, matches the number of IODEVs plus 1 (for the User 0 user). It is the presence of NUSERS greater than 1, and the different types of input/output devices, that differentiate a Model 204 Online job from a Batch job.

Other Model 204 run modes

The other modes of configuring and running Model 204 are called IFAM1, IFAM2, IFAM4, and BATCH2.