CCA Releases System 1032 ODBC Driver V2.1-0
By David Stone
Computer Corporation of America is pleased to announce the release of System 1032 ODBC Driver V2.1-0 for OpenVMS on the Alpha platform (the VAX release will follow soon). Using this product, Microsoft Windows based applications can access System 1032 datasets using the ODBC 2.5 API.
Users can access System 1032 datasets from products such as Visual C++, Visual Basic, Visual InterDev, Excel, and Access from Microsoft; as well as Borland Delphi, Sybase PowerBuilder, Seagate Crystal Reports, and many others.
Two of the major goals in the development of the product are performance and compatibility. The ODBC Driver performs many operations at near native System 1032 performance levels, because most of the work is actually done on the server by System 1032. Joins using the native System 1032 join mechanism result in a significant performance increase when compared with previous versions of ODBC Driver. Compatibility with the ODBC 2.5 standard is maintained throughout. The complete minimum SQL Grammar and many of the core and extended statements have been implemented, as have all core and level 1 functions and many level 2 functions of the ODBC API.
The System 1032 ODBC Driver meets the needs of a wide range of users, from those who need access to System 1032 datasets from Excel or Crystal Reports, to those who want to develop new applications. Query tools, Rapid Application Development (RAD) programs, and other off-the-shelf applications can be used with System 1032 datasets without coding changes or database modifications.
A prime area for development is in publishing System 1032 data on the World Wide Web. Using a Windows NT system running Microsoft Internet Information Server, products such as WebEngine or Visual InterDev can be used to quickly develop Web pages and applications that access System 1032 data and publish the results.
CCA will demonstrate the System 1032 ODBC Driver V2 at IMPACT'98, which is being held from June 1-3 in Miami, Florida (details at www.impactug.org, or from CCA support and sales representatives). The demo will include ad hoc queries, applications developed using RAD tools, and Web publishing.
If you would like an evaluation copy for in-house testing, please contact your sales representative.
CCA Television Profile Airs on BA* TV
Building America - Eye on Business is profiling Computer Corporation of America. Two viewing opportunities remain:
We hope that you will watch this informative program about CCA and its future plans. If you miss the program, or it is not being shown in your area and you would like a free videotape or CD-ROM of the CCA feature, contact CCA in the Framingham office at (508) 270-6666 x510, or send e-mail to: sharon_gilberti@cca-int.com.
For further information about BA*TV, check their Web site at http://www.batv.com.
From the IMPACT Committee:
"Bridge to 2000: Where do you want to be tomorrow?"
Hyatt Regency Miami Hotel, Miami, Florida
Join us at IMPACT'98, the leading international forum for users of Computer Corporation of America products Model 204, System 1032, and MarketPulse. IMPACT'98 welcomes managers, developers, DBAs, analysts, end-users, vendors, and customers - anyone with an interest in the products of Computer Corporation of America.
IMPACT'98 will provide tremendous learning opportunities. The Internet, the enterprise-wide server, and the Year 2000 challenge will be featured, along with all the latest developments, release enhancements, and application techniques. See the latest tools. Talk to software engineers. Learn from the experts. This is an excellent opportunity for education and training on the approaches and tools to satisfy the demands of information-hungry users!
***Early Bird Registration deadline is April 18, 1998!***
For details, call the IMPACT office at (781) 595-2005, send e-mail to admin@impactug.org, or access the IMPACT home page via: http://www.impactug.org.
Model 204
System 1032
Free - Model 204 V4R1 Update Class - Free Registration When You Register for IMPACT'98
Maximize your training dollars when you come to IMPACT'98. Register and attend IMPACT'98 and you can attend the June 4th Model 204 V4R1 Update Class for free! This special class, which begins the day after the conclusion of the IMPACT conference, will be held at the Hyatt Regency Miami Hotel. If you do not attend the conference, the cost is $350 per person.
Taught by CCA's Performance and Tuning guru Jim Damon, topics include:
You can register for the class on the IMPACT'98 registration form. Confirmation will be sent after receipt of conference registration. Space is limited and slots will be filled on a first-come-first-served basis. For IMPACT'98 registration and information, please contact the IMPACT office at (781) 595-2005, or send e-mail to admin@impactug.org
Perpetual Motion Machine: Model 204 Ring Streams and Perpetual
by Jim Damon
In Part 1 of this article (CCAPRINT Mar 98), I outlined the basic mechanism of ring-stream journaling. In Part 2, I'll discuss the following topics in more detail:
The following generalized schematic, which has been modified slightly from the first article, provides a good point of reference:
The following JCL and DEFINE commands are required for this stream:
//CTL DD DSN=JRNL.CTL,SPACE=(TRK,(1,1)),... //JRNL1 DD DSN=CCAJRNL1,SPACE=(CYL,90),... //JRNL2 DD DSN=CCAJRNL2,SPACE=(CYL,90),... //JRNL3 DD DSN=CCAJRNL3,SPACE=(CYL,90),... //CCAIN DD * DEFINE STREAM CCAJRNL WITH SCOPE=SYSTEM - RING=(JRNL1,JRNL2,JRNL3) - OFFLOAD=JRNLOFF - AUTOOFFLOAD=2 - CONTROL=CTL - CLOSE=NOAUTO DEFINE STREAM JRNLOFF WITH SCOPE=SYSTEM - CONCATENATE=(OFFL25,OFFL50,OFFL75,OFFL100) DEFINE DATASET OFFL25 WITH SCOPE=SYSTEM - DSN=OFFL25 VOLUME=TAP001 LABEL=SL - POSITION=1 UNIT=3480 DEFINE DATASET OFFL50 LIKE OFFL25 WITH SCOPE=SYSTEM - DSN=OFFL50 VOLUME=TAP002 DEFINE DATASET OFFL75 LIKE OFFL25 WITH SCOPE=SYSTEM - DSN=OFFL75 VOLUME=TAP003 DEFINE DATASET OFFL100 LIKE OFFL25 WITH SCOPE=SYSTEM - DSN=OFFL100 VOLUME=TAP004
Optimizing space allocation
The optimal size for the disk dataset - ring members JRNL1, JRNL2, and JRNL3 - is dependent on the capacity of the offload cartridge tape. Because AUTOOFFLOAD=2, two ring members are offloaded during each offload operation. Those two datasets should be sized to consume one offload tape. In this example, offloading to a 3480 cartridge, which has a capacity of 200M, consumes 180M with 20M to spare - a required margin of safety, because cartridge tapes vary slightly in length (number of feet) and, therefore, capacity.
The objective in sizing ring members then, is to maximize the use of each offload tape. Once an offload completes, that offload member is closed and remains closed for the remainder of the run regardless of remaining space available. Offloading to a 3480E cartridge (800M capacity) would accommodate (with AUTOOFFLOAD=2) ring members of approximately 390 cylinders each. Today, some cartridge tapes have even greater capacity; check with your tape vendor to determine your tape capacity.
Messages and warning track feature
The most important, informational messages are:
M204.1846: MEMBER membername OF RING STREAM CCAJRNL NOW ACTIVE This form of the 1846 message indicates that the previous ring member was filled and closed, and that journaling has switched to this member.
M204.1846: MEMBER membername OF CONCATENATED STREAM JRNLOFF NOW ACTIVE This second 1846 message indicates, if meaningful DDNAMES are used, how close the offload stream is to capacity. When all members defined to the offload stream have been used and all ring members are full, CCAJRNL is full and the run is terminated. The offload-stream DDNAMES used here signify that the offload stream is 25, 50, 75, and 100% full. With ten DDNAMES defined to the offload stream, the DDNAMES would be OFFL10, OFFL20, OFFL30, and so on. There is no practical limit to the number of DDNAMES, that is, tapes in this example, that can be defined to the offload stream; the more defined, the more times each ring member can be reused. When the next 1846 message is issued, indicating that MEMBER OFFL100 is now active, it is time to bump all users and bring the run down gracefully, before CCAJRNL fills.
M204.1320: OFFLOAD COMPLETE FOR MEMBER membername The 1320 message indicates that a ring member has been successfully offloaded and is now available for reuse.
Ring-stream related messages
The messages below, listed in reverse chronological order with VIEW ERRORS, were saved in the error-message-save table by setting ERRSAVE=200 in CCAIN and issuing the commands displayed in bold, also from CCAIN, during initialization.
MEMBER JRNL1 is opened and becomes the first active ring member following initialization, but no message is generated for this event.
MSGCTL M204.1320 SAVE OPER MSGCTL M204.1846 SAVE OPER
V ERRORS
00.48.14 1 15: M204.1320: OFFLOAD COMPLETE FOR MEMBER JRNL3 OF RING STREAM CCAJRNL 00.48.09 1 15: M204.1320: OFFLOAD COMPLETE FOR MEMBER JRNL2 OF RING STREAM CCAJRNL 00.48.02 1 15: M204.1846: MEMBER OFFL75 OF CONCATENATED STREAM JRNLOFF NOW ACTIVE 00.48.02 2 3: M204.1846: MEMBER JRNL1 OF RING STREAM CCAJRNL NOW ACTIVE 00.45.53 2 3: M204.1846: MEMBER JRNL3 OF RING STREAM CCAJRNL NOW ACTIVE 00.39.32 1 15: M204.1320: OFFLOAD COMPLETE FOR MEMBER JRNL1 OF RING STREAM CCAJRNL 00.39.27 1 15: M204.1320: OFFLOAD COMPLETE FOR MEMBER JRNL3 OF RING STREAM CCAJRNL 00.38.58 1 15: M204.1846: MEMBER OFFL50 OF CONCATENATED STREAM JRNLOFF NOW ACTIVE 00.38.58 1 0: M204.1846: MEMBER JRNL2 OF RING STREAM CCAJRNL NOW ACTIVE 00.38.21 1 0: M204.1846: MEMBER JRNL1 OF RING STREAM CCAJRNL NOW ACTIVE 00.37.58 1 15: M204.1320: OFFLOAD COMPLETE FOR MEMBER JRNL2 OF RING STREAM CCAJRNL 00.37.24 1 15: M204.1320: OFFLOAD COMPLETE FOR MEMBER JRNL1 OF RING STREAM CCAJRNL 00.37.07 1 15: M204.1846: MEMBER OFFL25 OF CONCATENATED STREAM JRNLOFF NOW ACTIVE 00.37.03 1 0: M204.1846: MEMBER JRNL3 OF RING STREAM CCAJRNL NOW ACTIVE 00.34.09 1 0: M204.1846: MEMBER JRNL2 OF RING STREAM CCAJRNL NOW ACTIVE
Evaluating your need for ring-stream journaling
Having now read in some detail of the complexity of implementing ring-stream journaling, you might ask, "Is this right for my organization?" One reader, who experimented with perpetual journaling, concluded that it was not really a requirement in his organization: "We easily eliminated most of the major contributors to our down-time [Model 204 recycling], and after a short while realised that these "quick wins" were giving us down-times consistently in the 10-12 minute timeframe. So we didn't have to do anything "fancy" [ring-stream journaling], because this was seen as an acceptable amount of down-time, especially as we used to be down for at least 45-60 minutes every night."
Perpetual journaling should be used only when operational requirements allow zero downtime for days on end. Otherwise, a single, CCAJRNL dataset (multiple-volumes, multiple extents are supported) and a recycle of Model 204 once a day, which usually takes no more than 15-20 minutes, should be the way that most organizations handle the problem of ever-increasing CCAJRNL datasets.
In a future article
In a future article, I will discuss:
Using ring-stream journals as CCARF datasets
Archiving ring-streams for future use by AUDIT204 or REGENERATE
Please address any questions or comments to me via e-mail at james_damon@cca-int.com.
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