All sessions with wait "mutex wait lru"

Hi, We have problem, IDS 14.10.FC13W1 was hung up. All sessions (open, activ, new ) were wait status "mutex wait lru" or "mutex wait hash". Do you have any idea what could cause this? What we should monitoring? ------------------------------ G W ------------------------------

G W: Most likely your buffer pools do not have enough LRU queues defined to prevent the large number of concurrent access requests to the buffer cache from having to wait for each other in order to modify pages in the cache. Increase the "lrus" field in the BUFFERPOOL parameters in your ONCONFIG file: BUFFERPOOL size=2K,lrus=8,lru_min_dirty=50,lru_max_dirty=60,extendable=1,start_memory=600000,memory=auto This is the setting in my tiny personal server that only has to deal with one or two active sessions. In most cases you should be setting something closer to the maximum value (512). You can monitor whether you have set it high enough be monitoring the Bufwaits Ratio (BR) metric. This is the calculation if you want to do it manually, or download the ratios.shr_ak package from my web site and install the ratios.sql stored procedure into sysmaster so you can run the newratios.ksh script which calculates BR and several other metrics that I use to get a quick view of the server's health: BR = (bufwaits / (pagreads + bufwrites)) * 100 Ideally you want your BR under 6. If it exceeds 7 you will begin to notice slowness and paused sessions. If it passes 10 your phone will begin to ring with complaints. I'm guessing that your BR is over 10.0 now. Download from www.askdbmgt.com/my-utilities.html Art ------------------------------ Art S. Kagel, President and Principal Consultant ASK Database Management Corp. www.askdbmgt.com ------------------------------

I'm afraid is nothing with configuration. Hung up happen 2 times since 4m (since upgrade) Profile dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached 128054408 435609255 9988961174 98.73 11422831 63399220 97369334 93.95 isamtot open start read write rewrite delete commit rollbk 10512212941 166858337 249984184 8487306818 20696625 3248052 2510590 2353998 153 gp_read gp_write gp_rewrt gp_del gp_alloc gp_free gp_curs 65181 2 99029 29 0 0 0 ovlock ovuserthread ovbuff usercpu syscpu numckpts flushes 0 0 0 22465.79 6264.73 451 13849 bufwaits lokwaits lockreqs deadlks dltouts ckpwaits compress seqscans 1753866 9246 11400184546 20 0 12918 2616365 2626144 ixda-RA idx-RA da-RA logrec-RA RA-pgsused lchwaits logpgs-RA 130350202 13139462 30404429 1823 89697592 3681658 1203 ------------------------------ G W ------------------------------

Hi please check DT463494 Deadlocks may be observed after long waits on the hash and lru mutexes. Newest version for 14.10.FC13 is 14.10.FC13W13 ------------------------------ Hedwig Fuchs ------------------------------

Hi, Can you post the stack from the threads with onstat -g stk? Regards, David. ------------------------------ David Williams Senior Database Platform Engineer Flutter London ------------------------------

Hi, Which versions are affected by DT463494? Regards, David. ------------------------------ David Williams Senior Database Platform Engineer Flutter London ------------------------------

G W: I agree, your BR is 0.33, so not the issue. I think that Hedwig nailed it and you are likely hitting a bug # DT463494. Upgrade to the latest release of 14.10 which is, as noted in Hedwig's post, 14.10.FC13W13. That release appears to have the fix for this as well as for a few other bugs and some security patches. Art ------------------------------ Art S. Kagel, President and Principal Consultant ASK Database Management Corp. www.askdbmgt.com ------------------------------