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3391527 - After seeing performance slow down and hitting deadlock warning message, IQ crash -SAP IQ

Symptom

  • Workload with a very high volume of transactions.
  • Delayed commits or general slowdowns could be observed.
  • IQ aborts with stack trace, after hitting:
    "Warning, s_bufpartition::GetCleanPage could not succeed in preventing the deadlock. Statement is being aborted after 5 failed tries"
  • Excerpt of IQMSG
    INFO s_bufpartition::GetCleanPage is working diligently to prevent a deadlock. Please be patient. retry=1, tid=139748094916352 s_buf=0x7f0ecbf1ba70 btype=13

    [bmp-trace-tout][rpbid] tid:139798531872512 bmp:0x7f24d40cd948 lbn:4796018 next-lbn:0 pbn:2013168404 nb: compr?1 updateNext?1
    Warning, s_bufpartition::GetCleanPage could not succeed in preventing the deadlock. Statement is being aborted after 5 failed tries,
    id=139798531872512 sbuf= 0x7f0ed3088500 btype= 1
                      | I I N I I H I I I I I I I I I I H I H I |
              Flags:  | s s e s s a s s n s s s s s s s a n e s |
                      | D D e V B s B C W S P U M Q S F s A a P |
                      | i i d e u B l h a p r s a u t r A f d r |
                      | r r s r s u o e s e e e p a a e f f O e |
                      | t t D s y s c c h c f r   r l e f i f A |
                      | i y e i   y k S A i e L   a e l i n T l |
                      | a   a o   W M u r a t o   n   i l n x i |
                      | b   l n   a a m e l c c   t   s i t n o |
            s_buf(s)  | l   l e   i p V a F h k   i   t t y L c |
            follow... | e   o d   t p a   L e e   n   P y A i a |
                      |     c     e e l   B d d   e   a   r s t |
                      |           r d i   u       d   g   e t e |
                      |           s   d   f           e   a   d |
    +----------------+-----------------------------------------+------------+------------+------------+------------+------------+------------+--------------+----------------+---
    ------------+
    |  &s_buf        | A D N V Y W B C I S P U M Q X F Z R H L | LockRefCnt | DBSpaceID  | BlkMapUID  | Blk Num    | _dskBlk    | BlockMap   | VersionRange | prev         | next           |
    +----------------+-----------------------------------------+------------+------------+------------+------------+------------+------------+--------------+----------------+----------------+
    0x7f0ed3088500 | a D n V y w B c i s p u m q x f z r h L |          0 |      16480 |    1069791 |    4796018 | 0x7f00ff377000 | 0x7f24d40cd948 |   2043015..2043015 |   0x7f0ed4244960 |   0x7f0ed2200850
    [2] Lock{slib/s_bufman.cxx:3399} UnLock{/home/iqabuild/views/links/r16.1.0_sp05_nbld_linux_64/gitsrc/cm/iqa/include/s_pageList.h:508}
    [1] Lock{slib/s_pageList.cxx:521} UnLock{/home/iqabuild/views/links/r16.1.0_sp05_nbld_linux_64/gitsrc/cm/iqa/include/s_pageList.h:508}
    [0] Lock{slib/s_bufman.cxx:6371} UnLock{slib/s_bufman.cxx:6447}
     
  • The 1rst stack in the stack trace might be relevant here.
  • Look into the entire stack trace for threads blocked in s_blockmap::Lock() or s_blockmap::Unlock() routines.
    ===== Thread Number 139807187334912 (IQ connID: 0000119920) =====
    <unknown>
    pcstkwalk
    ucstkgentrace
    <unknown>
    <unknown>
    <unknown>
    s_blockmap::Lock
    s_blockmap::s_blockmap


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Environment

SAP IQ 16.1

Product

SAP IQ 16.1

Keywords

828460; CR828460; CR#828460;  , KBA , BC-SYB-IQ , Sybase IQ , Known Error

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