As was diagnosed in ticket TS002495910, in customer's system "onstat -z" processing is causing about 1 second "block" every 5 minutes for all threads, that needed to acquire the global mutex. This causes problems in customer's system (one of the largest polish banks), which performs servicing card transactions (Visa, Mastercards, POS, etc.), as multiple sessions are blocked. Moreover, when checkpoint request is triggered at the time of such block, then all sessions modifying data are impacted - this is due to the fact, that the global mutex wait occurs within critical section, and that causes long wait time for threads going out of critical sections, while other sessions are prohibited from entering critical sections.
The problem impacts all customer's of the bank and also all institutions Poland wide, which perform card payment transaction validation in this bank's system (an example of such institution is Poland wide petrol station operator). For example the 1 second "block" causes Visa or Mastercard transactions to be rejected at the time of block.
Currently there is no workaround for this behaviour - to eliminate the problem "onstat -z" was disabled for the time being.
Why is it useful?
|Who would benefit from this IDEA?||All people using bank's card payments, as well all people Poland wide paying in institutions, which are being serviced by the bank.|
How should it work?
|Priority Justification||Due to the impact of the problem (all people using bank's card payments, all people Poland wide paying in institutions, which are being serviced by the bank) the solution would be needed quickly.|
|Customer Name||Santander Bank|
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