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  • In Linux, the user can also check the CPU for each thread with the top command. If executed with the top -H option, the search is performed for each thread. However, it is possible only if the installed procps version is 3.2.7 or later.
    If not, simply check as follows. (Not well supported in lower version)

    Code Block
    themeDJango
    languagebash
    Shell> ps -LFm -p <process id>
UID          PID  PPID   LWP  C NLWP    SZ   RSS PSR STIME TTY          TIME CMD
altibase    7153     1     -  8   47 921763 896248 - 16:53 ?        00:10:50 /home/lim272/altibase_home/bin/altibase -p b
altibase       -     -  7153  0    -     -     -   2 16:53 -        00:00:00 -
altibase       -     -  7154  0    -     -     -   0 16:53 -        00:00:00 -
altibase       -     -  7163  0    -     -     -   7 16:53 -        00:00:10 -
altibase       -     -  7164  0    -     -     -   1 16:53 -        00:00:10 -
altibase       -     -  7165  2    -     -     -   1 16:53 -        00:03:20 -

    LWP is a unique number for each thread, and the value displayed in the C item is the CPU usage rate.

     Description
    CPUCPU share that the thread is currently using
    LWPIDUnique number of thread

pstack

...

  • Like pstack, when checking the CPU occupancy of a thread, it is used as a way to check what part the thread is currently executing.

     

    Code Block
    themeDJango
    languagebash
    Shell> pstack <process id>
Thread 45 (Thread 0x7f8d27794700 (LWP 7164)):
#0  0x00007f8d2e8669b3 in epoll_wait () from /lib64/libc.so.6
#1  0x0000000000f5e761 in cmnDispatcherDetectSOCKEpoll(cmnDispatcher*, iduList*, unsigned int*, PDL_Time_Value*) ()
#2  0x0000000000f49dcb in cmiSelectDispatcher(cmnDispatcher*, iduList*, unsigned int*, PDL_Time_Value*) ()
#3  0x000000000042a4fc in mmtServiceThread::findReadyTask(PDL_Time_Value*) ()
#4  0x000000000042cfb7 in mmtServiceThread::run() ()
#5  0x0000000000f80da2 in idtContainer::staticRunner(void*) ()
#6  0x00007f8d2f796df3 in start_thread () from /lib64/libpthread.so.0
#7  0x00007f8d2e8663dd in clone () from /lib64/libc.so.6
Thread 44 (Thread 0x7f8d26bf3700 (LWP 7165)):
#0  0x0000000000e6660e in smnnSeq::fetchNext(smnnIterator*, void const**) ()
#1  0x0000000000ec70ce in smiTableCursor::readRow(void const**, scGRID*, unsigned int) ()
#2  0x00000000006b83f2 in qmnSCAN::readRow(qcTemplate*, qmncSCAN*, qmndSCAN*, int*) ()
#3  0x00000000006b851b in qmnSCAN::doItNext(qcTemplate*, qmnPlan*, int*) ()
#4  0x00000000006b710b in qmnSCAN::doIt(qcTemplate*, qmnPlan*, int*) ()
#5  0x0000000000887a1a in qmnJOIN::doItRight(qcTemplate*, qmnPlan*, int*) ()
#6  0x0000000000887c3f in qmnJOIN::doIt(qcTemplate*, qmnPlan*, int*) ()
#7  0x0000000000881b14 in qmnHSDS::doItDependent(qcTemplate*, qmnPlan*, int*) ()
#8  0x0000000000881c4f in qmnHSDS::doIt(qcTemplate*, qmnPlan*, int*) ()
#9  0x00000000006bb2a4 in qmnPROJ::doIt(qcTemplate*, qmnPlan*, int*) ()
#10 0x00000000004d27cf in qci::moveNextRecord(qciStatement*, smiStatement*, idBool*) ()
#11 0x000000000043f682 in mmtServiceThread::fetch(cmiProtocolContext*, mmcSession*, mmcStatement*, unsigned short, unsigned short, unsigned short, unsigned int) ()
#12 0x00000000004402ad in mmtServiceThread::fetchProtocol(cmiProtocolContext*, cmpProtocol*, void*, void*) ()
#13 0x0000000000f4b477 in cmiRecv(cmiProtocolContext*, void*, PDL_Time_Value*, void*) ()
#14 0x000000000042a7ef in mmtServiceThread::executeTask_READY(mmcTask*, mmcTaskState*) ()
#15 0x000000000042c355 in mmtServiceThread::executeTask() ()
#16 0x000000000042c922 in mmtServiceThread::multiplexingAsShared() ()
#17 0x000000000042cfb7 in mmtServiceThread::run() ()
#18 0x0000000000f80da2 in idtContainer::staticRunner(void*) ()
#19 0x00007f8d2f796df3 in start_thread () from /lib64/libpthread.so.0
#20 0x00007f8d2e8663dd in clone () from /lib64/libc.so.6

     

    Since all of the above results are output for each thread, classify each thread and check from the bottom to the top within the paragraph. In the example above, Thread 44 (LWP:7165) is in the following order.

     Description
    clone start_thread staticRunner run multiplexingAsShared execute_Task execute_Task_READYcreating and starting a thread
    cmiRecvThe user's query request has been read in the communication
    mmtServiceThread::executeProtocol mmtSerivceThread::execute doExecuteEnter the execution stage
    mmcStatement::execute mmcStatement::executeDML qci::execute qmx:executeInsertSelect qmnINST:doItNext qmnINST:insertOneRow smiTableCursor::insertRow smiTableCursor::normalInsertRow smcRecord::insertVersionCheck the execution of Insert statement
    smcRecordUpdate::writeInsertLog smxTrans::writeTransLog smrLogMgr::writeLogWrite redo log to execute insert statement
    smLogMgr::updateTransLSNInfo smxTrans::setLstUndoNxtLSNUpdate transaction lsn for undo
    iduPosixLockAcquire a lock on a thread

    By looking at the information of ps/pstack as shown above, it is possible to check what specific thread that uses the most CPU is performing. Also among many SQL statements, a more narrow trace can be made with the above pstack results.

Checking the list of files in use

...

  • If a separate utility, such as lsof in Linux, is not installed, do the following.

    Code Block
    themeDJango
    languagebash
    Shell> ls -l /proc/<process id>/fd 
lrwx------ 1 altibase altibase 64 Aug 14 18:56 44 -> socket:[130274146]
lrwx------ 1 altibase altibase 64 Aug 14 18:56 46 -> /home/altibase/altibase_home/logs/logfile21
lrwx------ 1 altibase altibase 64 Aug 14 18:56 47 -> /home/altibase/altibase_home/logs/logfile22
lrwx------ 1 altibase altibase 64 Aug 14 18:56 48 -> /home/altibase/altibase_home/logs/logfile23
lrwx------ 1 altibase altibase 64 Aug 14 18:56 49 -> /home/altibase/altibase_home/logs/logfile24

    In Linux, various information can be checked under the /proc/<process id> path, so please refer to the related information.

System Log

...

  • Check the files that exist in /var/log/. Generally, check the messages file.

SUN

...

  • These are commands based on Solaris 5.10.

prstat

...

  • Altibase is developed in the thread structure, and this command is used to check which thread occupies and uses a lot of CPU in some cases.

    Code Block
    Shell> prstat -L -p <process id> <refresh interval>
Ex) prstat -L -p 22951 1   (Means to view the process in 1 second)
PID      USERNAME      SIZE   RSS   STATE  PRI NICE   TIME  CPU   PROCESS/LWPID
22951    altibase      502M  106M   sleep   59    0   0:22:50   1.7%   altibase/5
22951    altibase      502M  106M   sleep   59    0   0:23:49   0.3%   altibase/4
22951    altibase      502M  106M   sleep   59    0   0:00:10   0.1%   altibase/12
22951    altibase      502M  106M   sleep   59    0   0:00:05   0.1%   altibase/47
22951    altibase      502M  106M   sleep   59    0   0:25:28   0.0%   altibase/6
22951    altibase      502M  106M   sleep   59    0   0:22:19   0.0%   altibase/9
22951    altibase      502M  106M   sleep   59    0   0:23:13   0.0%   altibase/8

pstack

...

  • Similar to prstat, when checking the CPU occupancy of a thread, it is used as a way to check what part the thread is currently executing.

    Code Block
    themeDJango
    languagebash
    Shell> pstack -F <process pid> | c++filt
-----------------  lwp# 7 / thread# 7  --------------------
ffffffff7e1d9ce8 pollsys  (ffffffff7b4ffa50, 0, ffffffff7b4ffb10, 0)
ffffffff7e173c44 pselect (0, ffffffff7b4ffa50, ffffffff7e344710, ffffffff7e344710, ffffffff7b4ffb10, 0) + 1f0
ffffffff7e173fe8 select (0, 106eea070, 0, 0, ffffffff7b4ffbd8, fffc00) + a0
00000001006f6df4 IDE_RC cmnDispatcherSelectSOCK(cmnDispatcher*,iduList*,unsigned*,PDL_Time_Value*) (106eea040, ffffffff7b4ffd88, 0, 106cc5818, ffffffff, 106eea070) + 50
00000001006f089c IDE_RC cmiSelectDispatcher(cmnDispatcher*,iduList*,unsigned*,PDL_Time_Value*) (106eea040, ffffffff7b4ffd88, 0, 106cc5818, ffffffffffffffff, 1006f6da4) + 1c
0000000100140790 void mmtServiceThread::findReadyTask() (106cc56d8, 105966f18, 101000, 0, 2710, 0) + 14
000000010013f878 void mmtServiceThread::run() (106cc56d8, 1, ffffffffffffffff, 2ec6bb9, 101329000, 10132b000) + 560
0000000100717034 void*idtBaseThread::staticRunner(void*) (106cc56d8, 100000, 0, 0, 100a120c8, 10013f318) + 14
ffffffff7e1d609c _lwp_start (0, 0, 0, 0, 0, 0)

    The c++filter command is used to remove the case where the function named called between C/C++ is not displayed properly. When not used, the function name is displayed in a form that is difficult to see, so it is possible to use it. Generally, it exists where the executable file of the path where the compiled is installed is located. (Ex: /opt/SUNwspro/bin/)
    In the same way as the method of interpreting the result of pstack, it is divided into paragraph units based on lwp# for each thread and interpreted from bottom to top.

pfiles

...

  • Similar to prstat, when checking the CPU occupancy of a thread, it is used as a way to check what part the thread is currently executing.

    Code Block
    themeDJango
    languagebash
    Shell> pfiles -F <process id>
22951:  /home2/altibase/work/altibase_home/bin/altibase -p boot from admin
Current rlimit: 65535 file descriptors
0: S_IFREG mode:0644 dev:118,38 ino:3309572 uid:124 gid:1 size:202128
O_WRONLY|O_APPEND|O_CREAT|O_LARGEFILE
/home2/altibase/work/altibase_home/trc/altibase_boot.log
1: S_IFREG mode:0644 dev:118,38 ino:3309573 uid:124 gid:1 size:1413256
O_WRONLY|O_APPEND|O_CREAT|O_LARGEFILE
/home2/altibase/work/altibase_home/trc/altibase_sm.log

    In the above result, all the files accessed by the process in the order of 0 and 1 along with the currently available file descriptor information are shown.
    When running pfiles while multiple sessions are connected, all data files, trace logs, transaction log files, and even a list of communication connections are displayed.

    Code Block
    themeDJango
    languagebash
    321: S_IFSOCK mode:0666 dev:329,0 ino:63732 uid:0 gid:0 size:0
O_RDWR|O_NONBLOCK 
SOCK_STREAM
SO_REUSEADDR,SO_KEEPALIVE,SO_SNDBUF(65536),SO_RCVBUF(32788),IP_NEXTHOP(0.0.128.20)
sockname: AF_INET 127.0.0.1  port: 27584
peername: AF_INET 127.0.0.1  port: 42567

System Log

...

  • During the technical support, if the user needs to find the cause from outside, SUN should check /var/adm/messages. The file extension means the week the log was recorded, and the log of the week including today is recorded in the messages file.

    Code Block
    Shell> vi /var/adm/messages
Feb 24 18:08:24 v880    Corrupt label; wrong magic number
Feb 24 18:08:24 v880 scsi: [ID 107833 kern.warning] WARNING: /pci@9,700000/fibre-channel@4/fp@0,0/ssd@w210000d023041a42,7 (ssd13):
Feb 24 18:08:24 v880    Corrupt label; wrong magic number
Feb 24 18:08:24 v880 scsi: [ID 107833 kern.warning] WARNING: /pci@9,700000/fibre-channel@4/fp@0,0/ssd@w210000d023041a42,7 (ssd13):
Feb 24 18:08:24 v880    Corrupt label; wrong magic number