IDS 7.31 migration HPUX to AIX ?

Hi all, I have a customer planning to migrate a large IDS 7.31.UD4 OLTP application from HPUX 11 to AIX 5.2 (32 bit) I am looking for any experiences,resources, articles or information addressing AIX specific IDS bugs and gotchas [as well as that specific migration] Is there a recommended version of IDS 7.31 for that platform? Is there a preference for either 32 or 64 bit? I'm really interested in anything information I can find on IDS on AIX 5. Thanks in advance, Peter

Dear Peter I have attched two SAP Notes regarding Informix IDS on AIX . The topics of the notes are generic , though . Regards Tilman SAP-Note No. 675173 Short description: Informix error 25587 on AIX 5.x ---------------------------------------------------------------------------- Symptom ------- Work processes terminate sporadically with Informix error -25587 on AIX 5.1. Sometimes work processes may hang. Other terms ----------- IPC, link, shared memory, -25587, network, POWER4, PTS bug 161668, AIX 5 Reason and Prerequisites ------------------------ You are using AIX 5.x with a POWER4 processor. SAP work processes (WP) terminate sporadically with error 25587 'Network receive failed'. There are corresponding entries in the syslog or the WP log file (dev_w*). This only affects work processes using the Interproces Communication Protocoll (shared memory link) for communication with the database server. This is caused by error PTS 161668 in the Informix-ESQL/C libraries. PTS 161668 SHARED MEMORY CONNECTIONS HANG ON AIX POWER4 SYSTEMS Solution Only use TCP/IP as a link log. o Convert the database to a TCP/IP link Create a new service in the file /etc/services as a user "root" and call it "sapinf<SID>a" (Caution: use a service number that has not been assigned yet!). Note that with activated NIS, NIS+ or a similar service the change must be made in the respective master file. Example: If your system is called C11, for example, you should call the new service "sapinfC11a". The section from the /etc/services would now appear as follows: sapinfC11 4461/tcp sapinfC11a 4462/tcp Change the entry for the shared memory link as the user "informix" in the sqlhosts file ($INFORMIXSQLHOSTS). Example: If your system is called "C11", for example, and the database server is called "dbhost", this would produce the following entry in the sqlhosts file: dbhostc11shm onipcshm dbhost sapinfC11 Replace the log type as follows in the line: HPUX/AIX/LINUX/DEC: onipcshm -> onsoctcp SOLARIS: onipcshm -> ontlitcp Replace the service to be used with the newly created service, in other words replace "sapinfC11" with "sapinfC11a". The result should look as follows: HPUX/AIX/LINUX/DEC : dbhostc11shm onsoctcp dbhost sapinfC11a SOLARIS: dbhostc11shm ontlitcp dbhost sapinfC11a The change to TCP/IP as the link log does not adversely affect performance. If you then comment out the parameter NETTYPE for the SHM link in the Informix DB configuration file $ONCONFIG, this has the side effect that the address space is used better. This may offer substantial benefits with 32-bit database servers in particular (see note 407543). -------------------------------------------------------------------------------- --- -------------------------------------------------------------------------------- --- SAP-Note No. 407543 Short description: AIX: Shared Memory Management with Informix Symptom ------- No more SHM segments can be allocated on IBM AIX. This generally concerns 32-bit DB servers only. Other terms ----------- memory allocation, shared memory, ONCONFIG. Informix, configuration Reason and Prerequisites ------------------------ 32-bit processes on AIX can create only 10 (AIX<4.2.1) or 11 Shared Memory (SHM) segments. The size of a SHM segment is variable, however, every SHM segment uses an address space of 256MB. SHM segments larger than 256MB use multiple address spaces of 256MB. Thus, 32-bit processes have a maximum address space of 11 * 256MB = 2.75GB available for shared memory. A SHM segment created with a size of 260MB (266240 KB) for example, would thus use 2 * 256MB (=524288 KB) of address space; however, the useable memory for the process is only the 260MB with which the SHM segment was created. Thus you should make sure that SHM segments are only created with a size that is a multiple of 256MB. 64-bit processes also use 256MB of address space per SHM segment, however, far more SHM segments can be created. Solution Make sure that the 'resident' SHM segment of the Informix DB server is slightly below a multiple of 256MB. The size of the RESIDENT SHM segment is determined through the ONCONFIG parameters PHYSBUFF, LOGBUFF, BUFFERS, and LOCKS. PHYSBUFF and LOGBUFF are given in KB. BUFFERS determines the size of the database buffer in pages. In AIX, the size of a database page is 4KB. The parameter LOCKS determines the number of available database locks, every LOCK requires 44 bytes of memory. SHMVIRTSIZE should be a multiple of 262144KB.!Caution: Under AIX 4.3, the maximum size for a single SHM segment is 2097152KB (2GB). SHMADD should always be set to 262144KB. Use only TCP/IP for the connection protocol. The connection to the DB server can be made over TCP/IP or also over IPC (i.e. shared memory) locally. In the latter case, the db server creates a so-called 'Message' SHM segment. This is generally small, but uses 256MB of address space nevertheless. If 'Shared Memory' is a bottleneck, you should use TCP/IP for connection setup locally as well; in that case you can do without the 'Message' SHM segment. For this, set the parameters DBSERVERNAME and DBSERVERALIASES to TCP/IP connections from $INFORMIXSQLHOSTS and delete the parameter NETTYPE for the IPC communication from the $ONCONFIG. Please see note 111876 describing the procedure for connecting a 32-bit kernel to a 64-bit DB for more information. No negative consequences on the performance need to be feared. Check the size of the requested shared memory with the command 'onstat -g seg' and 'ipcs -m -a'. -- Tilman Model-Bosch IBM Data Managment Solutions, Informix Advanced Support c\\\\o SAP AG TECHDEV 05 Neurrotstr.16 69190 Walldorf "PETER SIEGEL" <psiegel@us.ibm.c To: ids@iiug.org om> cc: Sent by: Subject: IDS 7.31 migration HPUX to AIX ? [2445] forum.subscriber@ iiug.org 01/19/2004 08:59 PM Hi all, I have a customer planning to migrate a large IDS 7.31.UD4 OLTP application from HPUX 11 to AIX 5.2 (32 bit) I am looking for any experiences,resources, articles or information addressing AIX specific IDS bugs and gotchas [as well as that specific migration] Is there a recommended version of IDS 7.31 for that platform? Is there a preference for either 32 or 64 bit? I'm really interested in anything information I can find on IDS on AIX 5. Thanks in advance, Peter