457!!!!!!!!!!!!!!!!!!!!!

Dear MaryAnn Better Subject: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Nightmares!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!! The following was the text I wrote to another person who is experiencing the same problem: [16/2/96_____________________________ We am working with PowerBuilder Enterprice 4.0 (under Windows 3.11 - in a PC 486 DX266 16MB RAM) Informix OnLine 5 and I-Net 5.0 (under Unix on a Unisys machine) The net works with TCP/IP (win 32 or PCTCP) Sometimes and sudenly when the application executes a Datawindow Retrieve (SELECT) instrucction, I-net reports the error num. -457 that means something like "Yor process have been kill" (well, you know the text of this error) and my PB aplication is disconected from informix (this is: the sqlturbo process hangs!! expontaniusly!!!!!!). This error happens very often - so you can imagine what the users are saying! (Another error like "To many hosts variables are passed to the server" (-257) were also reported, but we have avoided it using a tric in PB!) Trying to solve the -457 error we have made the changes in the system parameters (Unix and Informix): Informix Parameters: SPINCNT BUFFERS MEMORY SEGMENTS TIMEOUTS Etc. Unix Parameters: The ones related with semafores The ones related with shared memory segments size We are looking for timeouts, but the are no clues. Now are almost convinced that the source of the problem is the NetWork. But who knows? And the amazing thing is that the online.log file reports the same information that you are telling me: "09:40:16 Process Aborted Abnormally: pid=7371 user=1681 us=800e51a4 flags=1" And, we are also "surprised and dismayed that *no* page errors/bitmap errors, etc., showed up in the log". ???????? By internet I have received some clues that point to the following sorces of our problem: -BUG in I-NET 5.0WF1 -BUG in Informix Online 5.01 -BUG in PowerBuilder -Unix timeouts settings -Network timeout settings, sockets settings Well, I think we can help each other, as we are now sharing part of our lifes (thought not the best parts of them). I would like you to take a look at the mails I have received! To see if this can help you! Please lets keep in touch! And let me tell you that I also will appreciate a lot any help you can pass to me. Good Luck! ________________________________________ ******************************************************** A mounth later............................I wrote ******************************************************** [12/3/96_________________________________ >>A hope in -457?<< Means that maybe we are getting to the end of this nightmare. Today I was informed by Informix Suport here in Colombia of a known bug on I-NET. Informix Colombia forwarded our case to Informix Suport for Latin America (Miami) and they informed about the I-NET Bug. It seems that the new I-Net version that solution the bug will be available at the end of March. Well, as we were getting in some trouble with our customer (because of the -457) , we ask Informix to send as a formal document reporting the I-Net bug. I hope this helps a little till we get the patches. Personally, I really don't trust anybody until definitely seeing our application complety free of -457's. _________________________________________ ********************************************************* And now, we are waiting for the new I-NET 5.01WJ1 (that corrects the 5.01 WF1) If you are using another version, don't panic It still coluld be a BUG; I have received 2 e-mails related with I-NET Bugs in other versions. Informix send to us the following possible workarroung. We didn't implanted this solution because we think this is a solution for simple applications - and in our case, if we do what they propose we could have database integrity and concurrence problems. [INFORMIX WORKARROUND_____________ The application programmers modified the PowerBuilder 4.0 code so that there are close/open database statements done to disconnect after a query. It seems to work; there have been no -457 errors. BACKGROUND The primary mechanism for a PowerBuilder application to talk to a database server is a datawindow object. A datawindow in turn uses a tranaction object to communicate to the server, typically SQLCA. An application may use one of two functions to assoicate a datawindow with a transaction object. SetTransObject() and SetTrans(). One of these functions must be called in order for the datawindow to work with the database. SetTransObject() -- This function requires explicit transaction control to be implemented in the application and uses an already established connection. Example: CONNECT USING SQLCA: // Open a live connection to dbms dw_1.SetTransObject(SQLCA) // Tell datawindow how to connect dw_1.Retrieve() // get data from dbms COMMIT USING SQLCA; // release locks if held DISCONNECT using SQLCA; // close connection to dbms SetTrans() -- this function uses an existing transaction object to create a new transaction object which is used to establish a new connection. Transaction management is performed internally and the connection is disconnected once the operation is complete. Example: dw_1.SetTrans(SQLCA) dw_1.Retrieve() // Connects, Selects, commits and disconnects all here The PMIS application uses the SetTransObject() method to interact with the database. It connects once when the application is first started, may do numerous database operations, then disconnects only when the application closes. THE PROBLEM For some undetermined reason the database connection is dropped at the server resulting in an SQL Error 457. It appears to be related to some threshold being achieved. For instance, some reports can be run once, but not twice in the same session. Some reports run in a simple form but die when made more complex, such as by addition addition where criteria. THE WORKAROUND By using the SetTrans() method instead of SetTransObject() the problem has been drastically reduced, if not eliminated. This is at the cost of adding many Connect-Operation-Disconnect cycles to the application processing. The observed performance impact has been slight in the development region and is unknown in a production environment. Any potential side effects are also unknown. _________________________________ *********************************************** I will post to you MaryAnn all the related e-mails I have received! (About 12) Maybe you'll get some e-mails twice - but sorry If anyone on the list wants me to post this 12 mails please feel free to e-mail me. Bye _______________________ Juan Gabriel Mejia jmejia@uniandes.edu.co _______________________