Symptom Accessing the table received lock timeout: db2 'select count(*) from MYTAB' SQL0911N The current transaction has been rolled back because of a deadlock or timeout. Reason code "68". SQLSTATE=40001   Cause This happens because after offline Reorg of table is interrupted at the index creation phase, indexes are marked invalid. Following this event, any attempt to access the table will trigger index rebuilding for the table. A typical stack of the agent working on index rebuilding is as follows:   [1]... [More]

Summary: Command admin_move_table receives SQL0270N (Reason code = "52").for a partition table which uses generated column as partitioning key   Details: The table is defined as follows, note the partitioning key is a generated column. CREATE TABLE MYTAB ... "SUBKEY" VARCHAR(96 OCTETS) NOT NULL IMPLICITLY HIDDEN GENERATED ALWAYS AS (SUBSTR(KEY,1,32)))..PARTITION BY RANGE("SUBKEY")...   Trying to use admin_move_table receives error: $ CALL SYSPROC.ADMIN_MOVE_TABLE ('DB2INST1', 'MYTAB',... [More]

In some customer's cases, I faced the situation that some customers wanted to restore and rollforward a specific tablespace from backup image due to the file system corruption on container files of that tablespace. Plus, they ask for the access to tables in other tablespaces without any down time.   Thus, for your understanding, I made a hands-on for 'online tablespace  restore and rollforward' . In this example, you will see ------------------------------------------- 1. the database is up and running 2. tables in... [More]

Tags:  rollforward online restore tablespace

After the IP address change on the machine,  Db2 instance couldn't be brought up. The error received was: $ db2start 01/01/2018 19:00:00 0 0 SQL6048N A communication error occurred during START or STOP DATABASE MANAGER processing. SQL1032N No start database manager command was issued. SQLSTATE=57019 The following messages are found in db2diag.log:   2018-01-01-19.00.00.977600-240 I1094433E797          LEVEL: Severe PID     :1234                 TID :... [More]

Normally the storage group status is 0. The following is an example that the storage group status is set to 0x0000000A instead: $ db2pd -d mydb -storagegroup Database Member 0 -- Database MYDB -- Active Standby -- Up 11 days 18:50:57 -- Date 2018-02-20-11.08.11.478864 Storage Group Configuration: Address           SGID Default  DataTag   Name 0x00003FFD04642820... [More]

Tags:  db2

In SAP environment, DB2_WORKLOAD is set to SAP. This is an aggregate registry variable and setting DB2_WORKLOAD to SAP automatically set DB2COMM to TCPIP: [i] DB2COMM=TCPIP [DB2_WORKLOAD]   In this environment, unsetting DB2COMM returns following error: db2inst1@bigmac:/home/db2inst1> db2set DB2COMM= DBI1302E  Invalid parameter detected. Explanation: An invalid parameter was used. User response: Use the -? option for the usage help message. If you want to temporarily disable DB2COMM, a workaround is to set SVCENAME in database... [More]

Tags:  db2

There are few  Technote and Document out there  on this already. But,   wanted to share this  as  some customers still faced this issue lately.   The  symptom is  reported as  sudden hang in  Db2 database.  Nothing progressing. CPU,  memory and I/O were abnormally idle in the box. That is an indication that nothing really running  and  stuck some where. No locking or latching.   A  quick  running  of  "db2pd -stack all"   will... [More]

Tags:  vintella hang plug-in authentication db2luw

After applying the Spectre/Meltdown patches  in RedHat  Linux  system hosting  Db2LUW database  connections were timing out. From Linux trace  it  was observed  db2's db2ckpwd  process was  issuing  getrlimit()  system call  many  number of times. Long loop of getrlimit and close. Example, 30607 13:48:58.283090 close(4) = 0 <0.000021> 30607 13:48:58.283159 getrlimit(RLIMIT_NOFILE, {rlim_cur=1024*1024, rlim_max=1024*1024}) = 0 <0.000019> 30607 13:48:58.283247... [More]

Tags:  getrlimit spectre db2ckpwd db2luw

== DEBUGGING CORE FILES [07] == STACK TRACE <-> SOURCE CODE [EXAMPLE 2] C program : example2.c [see at the end of entry] Platform : LINUX X86 Compilation: cc -m64 example2.c -o example2 Execution : ./example2 example2.c 12 # example2 example2.c 12 start time: 1519019133sec 111769nsec line = (null) [loop 5246992] Memory fault(coredump) Let's load the core file and print the stack: # gdb example2 mycore ... (no debugging symbols found)...done. Loaded symbols for /lib64/ld-linux-x86-64.so.2 ... [More]

Tags:  debug core file

== DEBUGGING CORE FILES [06] == STACK TRACE <-> SOURCE CODE [EXAMPLE 1] C program : example1.c [see at the end of entry] Platform : AIX Compilation: cc -q64 example1.c -o example1 Execution : ./example1 example1.c 99 # example1 example1.c 99 Segmentation fault(coredump) Let's load the core file and print the stack: # dbx example1 mycore Type 'help' for help. [using memory image in mycore] reading symbolic information ...warning: no source compiled with -g Segmentation fault in gettimeofday... [More]

Tags:  core debug file

== DEBUGGING CORE FILES [05] == STACK TRACE <-> SOURCE CODE We know now what is a stack trace, what help it can provide and how to read it. When a program is compiled with -g the stack trace will usually contain the line number in the source file. In that case it is quite easy to find the exact location in the source. It becomes a bit more complicated when the program was not compiled with -g and most of the time this is the case. To add to this many other things can make your quest even harder, to name a few only: static... [More]

== DEBUGGING CORE FILES [04] == STACK TRACE Now we know how to package, ship and load a core file. Question now is what can we do with it? Most likely anyone who is a bit familiar with C programming heard about 'stack'. But what is it really and how can it help when it comes to core file analysis? The 'stack' is a memory region dedicated to functions. It will provide storage for function's local variables as well as storage for special variables that will be used to guarantee flawless calls and returns between... [More]

Tags:  file core debug

== DEBUGGING CORE FILES [03] == HOW TO LOAD A CORE FILE IN A DEBUGGER? Once you have packaged the core file with all the objects required you need to load it into the debugger. If you are running the debugger on the same machine as the one where the core file was generated then not much of an issue, the debugger should be able to locate all required objects. However, if you are running the debugger on a different machine then you need to tell the debugger where to find the objects. So let's see how we can load the core file in... [More]

Tags:  file debug core

== DEBUGGING CORE FILES [02] == HOW TO PREPARE A CORE FILE FOR ANALYSIS? As we mentioned before the core file contains almost all regions that the running process had in it's address space. But not all. Among the missing ones are the 'text' regions. Those regions contains the various instructions that the process would execute. As well, the symbol tables that allow the debugger to print function names, are not included in the core file. Since viewing the assembly code (unless you compiled with -g) will most likely be a... [More]

Tags:  debug file core