RE: error -27001

Error 27001, Unable to connect via tcp network connections This article describes three common causes for listener-thread: err = -27001: Read error occurred during connection attempt errors. PROBLEM The error: listener-thread: err = -27001: Read error occurred during connection attempt. appears in the IBM® Informix® Dynamic Server (IDS) message log file (ONCONFIG configuration file parameter MSGPATH). Users are not able to connect to the database server. CAUSE / SOLUTION Three common causes and resolutions for the error are: 1. The connectivity files in the /INFORMIXTMP directory are not removed. The files are in the form of : VP.server_name.0100a server_name Database server name as was set in INFORMIXSERVER environment variable and associated with the tcp connections. Solution: Stop the database server, remove the files from the /INFORMIXTMP directory, and start the database server. 2. The ONCONFIG file settings for the NETTYPE parameter are not correct. This error is widely seen involving tcp network connections when the VP class in the NETTYPE setting is set for CPU vp. Solution: As a work around Change the vp class setting for the NETTYPE configuration parameter from CPU to NET. 3. An operating system resource limit was reached. Kernel parameters settings require changes. Solution: Check and possibly increase settings for the following kernel parameters or parameters equivalent to them depending on Unix platform: NOFILES SEMMNU NFILES MAXFILES MAXFILE_LIM Basim Chafik Senior Systems Analyst IBM Certified Advanced Technical Expert (CATE) 1.800.688.4895 basim.chafik@plx.com plexus (Division of BancTec) -----Original Message----- From: hariog@yahoo.com [mailto:hariog@yahoo.com] Sent: Wednesday, January 11, 2006 11:05 PM To: informix-list@iiug.org Subject: error -27001 Hi All, IDS 10.0.UC3 ELAS3.0, Kernel 2.4.21-4.ELsmp, RAID10 we have got some issues where connections are being dropped out and online records -27001 error. Database server and application server (4js) are on the same host. client application uses GDC 1.31.1e and connecting DB using ODBC (3.82.0000 2.81.TC3 client side). When -27001 occurs, no connection allowed during that time and application just hangs for about 3-4 mins and comes back to normal after that. We conatcted application provider and got a response back that they are testing GDC 1.32.1e which might fix this issue. I am not sure at this stage whether this read error is at client side or database side, however, I am suspecting some issues with database side which may or may not a contributing factor. Here are some snapshots: onstat -m 13:04:54 listener-thread: err = -27001: oserr = 0: errstr = : Readerror occurred during connection attempt. onstat -p IBM Informix Dynamic Server Version 10.00.UC3 -- On-Line -- Up 10 days 05:48:56 -- 1767052 Kbytes Profile dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached 350141411 812650455 72386225639 99.52 5767661 51497061 30441602 90.42 isamtot open start read write rewrite delete commit rollbk 58499395809 361322842 1054381511 54636023977 41832039 1749311 1049764 1527687 278 gp_read gp_write gp_rewrt gp_del gp_alloc gp_free gp_curs 31 0 0 0 0 0 52 ovlock ovuserthread ovbuff usercpu syscpu numckpts flushes 0 0 0 286317.00 43055.85 617 1972 bufwaits lokwaits lockreqs deadlks dltouts ckpwaits compress seqscans 15142198 20 45368091006 0 0 368 1158865 8541139 ixda-RA idx-RA da-RA RA-pgsused lchwaits 42083593 14215347 188961624 241266788 4988764 onstat -g spi IBM Informix Dynamic Server Version 10.00.UC3 -- On-Line -- Up 10 days 05:50:01 -- 1767052 Kbytes Spin locks with waits: Num Waits Num Loops Avg Loop/Wait Name 12 3756897 313074.75 mtcb vproc_sync_lock 232041 89433947 385.42 mtcb sleeping_lock 2 98 49.00 mtcb tcb_queue_lock 17 249360 14668.24 mtcb tcb_queue_lock 69 122322 1772.78 mtcb mutex_list_lock 99 99057 1000.58 mtcb notify_lock 102 22165 217.30 class cl_lock, class = 0 337731 47315091 140.10 vproc vp_lock, id = 1 243903 36604587 150.08 vproc vp_lock, id = 3 1725787 257670671 149.31 vproc vp_lock, id = 4 ..... ..... onstat -g glo IBM Informix Dynamic Server Version 10.00.UC3 -- On-Line -- Up 10 days 05:51:05 -- 1767052 Kbytes MT global info: sessions threads vps lngspins 293 461 31 2671 sched calls thread switches yield 0 yield n yield forever total: 2499649188 1174857135 1416527643 4898397 268246790 per sec: 2864 1201 1841 8 53 Virtual processor summary: class vps usercpu syscpu total cpu 3 281845.84 3847.27 285693.11 aio 22 3069.21 15118.16 18187.37 lio 1 18.39 95.39 113.78 pio 1 1.78 22.40 24.18 adm 1 10.56 109.81 120.37 soc 2 1327.41 23830.88 25158.29 msc 1 82.00 49.12 131.12 total 31 286355.19 43073.03 329428.22 Individual virtual processors: vp pid class usercpu syscpu total 1 6103 cpu 51524.72 1693.39 53218.11 2 6104 adm 10.56 109.81 120.37 3 6105 cpu 69208.90 1276.31 70485.21 4 6106 cpu 161112.22 877.57 161989.79 ..... ..... onstat -g ntd IBM Informix Dynamic Server Version 10.00.UC3 -- On-Line -- Up 10 days 05:53:47 -- 1767052 Kbytes global network information: #netscb connects read write q-free q-limits q-exceed alloc/max 303/ 391 162361 190897185 192280971 88/ 377 379/ 10 0/ 0 382/ 382 Client Type Calls Accepted Rejected Read Write sqlexec yes 162361 18 174875499 176469418 srvinfx yes 0 0 0 0 onspace yes 0 0 0 0 onlog yes 0 0 0 0 onparam yes 0 0 0 0 oncheck yes 0 0 15435546 15387710 onload yes 0 0 0 0 onunload yes 0 0 0 0 onmonitor yes 0 0 0 0 dr_accept yes 0 0 0 0 cdraccept no