Addressing OLTP Solutions with CICS: The Transaction Server ... - Ibm

More documents

Recommendations

Info

8.5.2 The Reference System 124 CICS for AIX as the Transaction Server provide universal access to the data, each CICS system would have to access the data remotely. This is quite easily done as long as both the CICS system and Encina SFS are in the same DCE cell. Again though, there is a performance overhead in accessing an Encina SFS remotely. The most immediate by-product is that fast local transport cannot be used between the CICS application server and the Encina SFS. • Have all of the facilities required In combining applications in the way in which we have suggested, you must remember to include all of the facilities that the applications require. For example, you may have to define more intersystem communication links because the applications being placed within a region each access different remote systems. • Are compatible Different applications may try to use the same temporary storage or transient data queue names, for example. If the names cannot be changed, the conflicting applications would have to remain separate. • Do not contain any affinities An application contains an affinity when, for example, it must be run in the same CICS system because a piece of data or state information that it requires is in that CICS system. From a workload management point of view, this is a bad characteristic for an application because it restricts the flexibility of making routing decisions. For a fuller description of the problems that you may encounter in running in this type of environment, see CICS/ESA Dynamic Transaction Routing in a CICSplex, SC33-1012-00. That book was written with a parallel transaction server environment in mind but contains useful information that is applicable in a parallel environment. 8.5.1.5 Summary You may find that moving to the multiple CICS systems we suggest here requires significant effort. Indeed it may not be achievable immediately, given the characteristics of some applications. It is a worthwhile goal to achieve, however, for a number of reasons: • Increased application availability • Better utilization of the available resources • Good growth capability. As the demands grow on the system, it is possible • to produce another instance of the common system and have it added to the workload management Transparent maintenance CICS SM workload management recognizes that machines have different processing capabilities. If one machine contains a faster processor than another, all else being equal, the first machine will process more work in a given period of time. To deal with these differences in processing capability, workload management uses a reference system. In an environment in which there are mixed processor speeds, it is possible to rank machines relative to each other. For example, the middle speed machine in your configuration might be given a relative speed of 1. Those machines that are slower would have a value of less than 1, and those that are faster would have a value of more than 1. If all machines were of
8.5.3 The Algorithm identical speed, they would all have the same relative speed values coded. A value of 1 would be sensible. It is important to set these values appropriately, particularly if there are machines of different speeds in your workload management configuration. The default is for all systems to be treated equally; that is, a relative speed of 1. To set the relative speed of a system you can edit the appropriate system model or system clone and specify a value for the speed of the system relative to the reference system. If you have a system model for each type of processor, set the value at the system model level. Otherwise you will have to set it at the system clone level. If the CICS system is subsequently moved to another machine with a different relative speed, you would have to amend the value accordingly. In this section we take a closer look at the workload management algorithm for selecting a system to which to route a piece of work. We discuss the principles of the algorithm rather than the specific parameters. For a description of the workload management parameters, see IBM CICS System Manager for AIX User′s Guide, SC33-1594-00. The overall effect of the workload management algorithm is for clients to choose a system clone for each work item based on the best information available. The choice is based on a simulation of information not available locally and historical data gathered by the clients themselves. There are two aspects to choosing a system clone on which to run an item of work: • Identifying the system clones that have the required application, transaction, or program • Choosing the system clone that provides the fastest service The workload management client identifies system clones that have the required resource from information in the local cache. It calculates a score for each system clone and selects the clone with the lowest score. If several system clones score equally, the algorithm selects one at random. This randomness ensures that work is spread evenly initially or after a quiet period. The total score of a system clone is the sum of scores representing the load already on that system, its health, the quality of the connection to the selector, its performance history, and the extra load that deciding to route the current work item to this system would cause: total_score = load_score + health_score + connection_score + history_score + projected_new_load_score The calculation of each of the above terms is dependent on parameters that are attributes of the requested resource model, the system clone being considered, its model, and the active configuration. These parameters are not discussed at any level of detail here. Chapter 8. Using CICS System Manager for AIX 125
Page 1:
Addressing OLTP Solutions with CICS
Page 4 and 5:
Take Note! Before using this inform
Page 6 and 7:
iv CICS for AIX as the Transaction
Page 8 and 9:
9.4 Security Issues on the Internet
Page 10 and 11:
viii CICS for AIX as the Transactio
Page 12 and 13:
x CICS for AIX as the Transaction S
Page 14 and 15:
xii CICS for AIX as the Transaction
Page 16 and 17:
The Team That Wrote This Redbook xi
Page 18 and 19:
xvi CICS for AIX as the Transaction
Page 20 and 21:
2 CICS for AIX as the Transaction S
Page 22 and 23:
1.2 Complex OLTP Business Environme
Page 24 and 25:
Figure 2. OLTP Complex for XYZ Insu
Page 26 and 27:
By using common application program
Page 28 and 29:
1.5 OLTP Market 10 CICS for AIX as
Page 30 and 31:
Figure 5. OLTP Market Segmentation
Page 32 and 33:
14 CICS for AIX as the Transaction
Page 34 and 35:
2.1 IBM Software Servers 2.1.1 Lotu
Page 36 and 37:
2.2.1 CICS Clients V1.1.0 A Transac
Page 38 and 39:
2.2.4 CICS Internet Gateway for AIX
Page 40 and 41:
3.1 Services CICS for AIX is a very
Page 42 and 43:
3.1.2 CICS API 24 CICS for AIX as t
Page 44 and 45:
3.1.3.1 Terminal Users and CICS Reg
Page 46 and 47:
3.2 Implementation 3.2.1 Components
Page 48 and 49:
3.2.2 Processes 3.2.1.3 Application
Page 50 and 51:
3.3.1 DCE RPC 3.3.2 TCP/IP 32 CICS
Page 52 and 53:
Figure 9. Interconnection Using Enc
Page 54 and 55:
connect to a PPC Gateway server mac
Page 56 and 57:
Figure 12. Interconnection Using TC
Page 58 and 59:
3.4.3 Configuration 3.4.4 Managing
Page 60 and 61:
3.4.6 Intersystem Communication CIC
Page 62 and 63:
3.4.8 Data Location 44 CICS for AIX
Page 64 and 65:
3.4.11 Operations plan to cope with
Page 66 and 67:
3.5 Summary 48 CICS for AIX as the
Page 68 and 69:
Figure 13. Application Server Model
Page 70 and 71:
4.2.1 CICS External Call Interface
Page 72 and 73:
By means of mapping files, you can
Page 74 and 75:
4.3 Versions 56 CICS for AIX as the
Page 76 and 77:
4.4 Sample Network Configurations 4
Page 78 and 79:
4.5.1 CICS Client for OS/2 60 CICS
Page 80 and 81:
4.5.2 CICS Client for DOS 62 CICS f
Page 82 and 83:
4.5.5 CICS Client for AIX CICS Clie
Page 84 and 85:
Page 86 and 87:
4.6 Summary 68 CICS for AIX as the
Page 88 and 89:
5.1.1 DCE Threads 5.1.2 Remote Proc
Page 90 and 91:
The GDS is based on the CCITT X.500
Page 92 and 93: egion or server it is looking for.
Page 94 and 95: 76 CICS for AIX as the Transaction
Page 96 and 97: 6.1.2 Encina Toolkit Server Core 6.
Page 100 and 101: is also necessary to use native AIX
Page 104 and 105: 7.1 X/Open XA Interface 7.1.1 X/Ope
Page 108 and 109: Communication between the transacti
Page 112 and 113: 7.2.2 Single-Phase and Two-Phase co
Page 116 and 117: Figure 28. Switching Access among D
Page 120 and 121: Figure 30. CICS Access to Remote DB
Page 122 and 123: emote DRDA database. Information ab
Page 124 and 125: As the COMMAREA has an allowable ma
Page 126 and 127: 7.5 Summary 108 CICS for AIX as the
Page 130 and 131: 8.2 Workload Management 112 CICS fo
Page 134 and 135: 8.4.2 System Management Application
Page 136 and 137: Figure 36. The CICS SM GUI 8.4.6 Di
Page 138 and 139: Figure 37. CICS SM Component Distri
Page 140 and 141: Figure 38. Combining Resources 122
Page 146 and 147: 8.6 Planning Considerations for CIC
Page 152 and 153: 9.1 Some Terminology 9.2 Services 1
Page 154 and 155: Figure 41. CICS Internet Gateway fo
Page 156 and 157: 9.3.3 Data Integrity The Web was or
Page 158 and 159: 9.3.5 High Availability The drawbac
Page 160 and 161: or employee records, eavesdropping
Page 164 and 165: • Type, size, and quantity of rec
Page 166 and 167: 10.3.3 Writing ECI and EPI Applicat
Page 168 and 169: The ANIMATOR debugging tool enables
Page 172 and 173: 10.8 Summary 154 CICS for AIX as th
Page 176 and 177: 11.1 The Big Picture 158 CICS for A
Page 178 and 179: 11.2 User Access 160 CICS for AIX a
Page 180 and 181: Figure 44. Access to Various DB2 Da
Page 184 and 185: takes place over TCP/IP or SNA comm
Page 186 and 187: provide greater protection in the u
Page 192 and 193:
Page 194 and 195:
How Customers Can Get ITSO Redbooks
Page 196 and 197:
Page 198 and 199:
design. The process of composing a
Page 200 and 201:
A year later ISC gave SQL formal in
Page 202 and 203:
Page 204 and 205:
designing efficient applications 15
Page 206:
IBML ® Printed in U.S.A. SG24-4752
show all

Addressing OLTP Solutions with CICS: The Transaction Server ... - Ibm

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?