Hi all, this is the situation: on a 3.9 box (see dmesg at bottom) with 256MB RAM, I am running a MySQL server, version 5.0.22 as installed from the packages.
Also, php5-core-5.0.5 and php5-mysql-5.0.5p0 are installed for apache to use. And on top of that, a user is running WordPress (wordpress.org), a PHP-over-MySQL application (looks like http://stare.cz/~nut/blog/) What happens is that _certain_ queries generated by the application make the mysql server SEGV (and restart) like this: 060830 15:15:19 1 Connect [EMAIL PROTECTED] on 1 Init DB nut 1 Query SELECT option_value FROM wp_options WHERE option_name = 'siteurl' 060830 15:15:20 1 Query SELECT option_name, option_value FROM wp_options WHERE autoload = 'yes' 1 Query SELECT option_value FROM wp_options WHERE option_name = 'ec3_num_months' LIMIT 1 1 Query SELECT option_value FROM wp_options WHERE option_name = 'ec3_nav_below' LIMIT 1 1 Query SELECT option_value FROM wp_options WHERE option_name = 'rewrite_rules' LIMIT 1 1 Query SELECT option_value FROM wp_options WHERE option_name = 'rewrite_rules' LIMIT 1 1 Query SELECT * FROM wp_categories 1 Query SELECT DISTINCT(post_id) FROM wp_post2cat WHERE category_id=13 1 Query SELECT DISTINCT * FROM wp_posts LEFT JOIN wp_post2cat ON (wp_posts.ID = wp_post2cat.post_id) WHERE 1=1 AND 0=1 AND (post_date_gmt <= '2006-08-30 13:15:59' AND id NOT IN (-1,38,39,41,104,110,130,136,140,159,161,162,175,181,182,184,197) ) AND (post_status = "publish") AND post_status != "attachment" AND category_id <> 2 AND category_id <> 3 AND category_id <> 4 AND category_id <> 5 AND category_id <> 6 AND category_id <> 12 AND category_id <> 10 AND category_id <> 11 AND category_id <> 13 AND category_id <> 14 AND category_id <> 15 AND category_id <> 16 AND category_id <> 18 AND category_id <> 19 AND category_id <> 20 GROUP BY wp_posts.ID ORDER BY post_date DESC LIMIT 0, 10 1 Query SELECT wp_postmeta.Post_ID FROM wp_postmeta WHERE meta_key = 'sticky' AND meta_value = '1' 1 Query SELECT DISTINCT * FROM wp_posts LEFT JOIN wp_post2cat ON (wp_posts.ID = wp_post2cat.post_id) WHERE 1=1 AND (post_date_gmt <= '2006-08-30 13:15:59' AND id NOT IN (-1,38,39,41,104,110,130,136,140,159,161,162,175,181,182,184,197) ) AND (post_status = "publish") AND post_status != "attachment" AND category_id <> 2 AND category_id <> 3 AND category_id <> 4 AND category_id <> 5 AND category_id <> 6 AND category_id <> 12 AND category_id <> 10 AND category_id <> 11 AND category_id <> 13 AND category_id <> 14 AND category_id <> 15 AND category_id <> 16 AND category_id <> 18 AND category_id <> 19 AND category_id <> 20 GROUP BY wp_posts.ID ORDER BY post_date DESC LIMIT 0, 10 mysqld got signal 11; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. key_buffer_size=67108864 read_buffer_size=258048 max_used_connections=1 max_connections=100 threads_connected=1 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_connections = 141935 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. 060830 15:15:20 mysqld restarted [...] Now, not that the queries aren't stupid (it's a blogging PHP application, 'nough said?), but anyway: why does MySQL SIGSEGV? The relevant (IMHO) piece of /etc/my.cnf says key_buffer = 64M table_cache = 128 sort_buffer_size = 512K net_buffer_length = 8K read_buffer_size = 256K read_rnd_buffer_size = 512K myisam_sort_buffer_size = 8M max_allowed_packet = 1M query_cache_size= 16M thread_concurrency = 2 thread_cache = 8 When I made all the buffers half, result was the same. Also, there usually IS 141935K of free memory (for mysql to use). I wonder what is really happening. Does mysql not have enough memory (as restricted by my.cnf) to process the query? Am I giving MySQL too much memory (as specified in my.cnf) so that, on a 256 RAM machine, it gets killed? This happens whenever this query is sent to the server; OTOH, various other PHP/MySQL based applications run on the server without problems. Why does the system send SIGSEGV to the MySQL server? Because it violates segmentation, right? So is this MySQL's fault? Or is it a missconfiguration of my.cnf? Any hint appreciated. Thanks for your time Jan OpenBSD 3.9 (GENERIC) #617: Thu Mar 2 02:26:48 MST 2006 [EMAIL PROTECTED]:/usr/src/sys/arch/i386/compile/GENERIC cpu0: Intel Celeron ("GenuineIntel" 686-class, 128KB L2 cache) 432 MHz cpu0: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR real mem = 268005376 (261724K) avail mem = 237555712 (231988K) using 3297 buffers containing 13504512 bytes (13188K) of memory mainbus0 (root) bios0 at mainbus0: AT/286+(a5) BIOS, date 08/17/00, BIOS32 rev. 0 @ 0xfd7a0 pcibios0 at bios0: rev 2.1 @ 0xfd7a0/0x860 pcibios0: PCI IRQ Routing Table rev 1.0 @ 0xfdf30/176 (9 entries) pcibios0: PCI Interrupt Router at 000:07:0 ("Intel 82371FB ISA" rev 0x00) pcibios0: PCI bus #1 is the last bus bios0: ROM list: 0xc0000/0x8000 0xc8000/0x800 0xe0000/0x4000! 0xe4000/0xc000 cpu0 at mainbus0 pci0 at mainbus0 bus 0: configuration mode 1 (no bios) pchb0 at pci0 dev 0 function 0 "Intel 82443BX AGP" rev 0x03 ppb0 at pci0 dev 1 function 0 "Intel 82443BX AGP" rev 0x03 pci1 at ppb0 bus 1 pcib0 at pci0 dev 7 function 0 "Intel 82371AB PIIX4 ISA" rev 0x02 pciide0 at pci0 dev 7 function 1 "Intel 82371AB IDE" rev 0x01: DMA, channel 0 wired to compatibility, channel 1 wired to compatibility wd0 at pciide0 channel 0 drive 0: <WDC WD600BB-00CAA1> wd0: 16-sector PIO, LBA, 57241MB, 117231408 sectors wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 2 atapiscsi0 at pciide0 channel 1 drive 0 scsibus0 at atapiscsi0: 2 targets cd0 at scsibus0 targ 0 lun 0: <LITEON, CD-ROM LTN403, DL1M> SCSI0 5/cdrom removable cd0(pciide0:1:0): using PIO mode 4, Ultra-DMA mode 2 uhci0 at pci0 dev 7 function 2 "Intel 82371AB USB" rev 0x01: irq 9 usb0 at uhci0: USB revision 1.0 uhub0 at usb0 uhub0: Intel UHCI root hub, rev 1.00/1.00, addr 1 uhub0: 2 ports with 2 removable, self powered piixpm0 at pci0 dev 7 function 3 "Intel 82371AB Power" rev 0x02: SMI iic0 at piixpm0 "unknown" at iic0 addr 0x18 not configured lmenv0 at iic0 addr 0x2d: adm9240 rev 2, starting scan "unknown" at iic0 addr 0x4e not configured xl0 at pci0 dev 15 function 0 "3Com 3c905C 100Base-TX" rev 0x74: irq 10, address 00:50:da:49:94:74 bmtphy0 at xl0 phy 24: Broadcom 3C905C internal PHY, rev. 6 isa0 at pcib0 isadma0 at isa0 pckbc0 at isa0 port 0x60/5 pckbd0 at pckbc0 (kbd slot) pckbc0: using irq 1 for kbd slot wskbd0 at pckbd0: console keyboard vga0 at isa0 port 0x3b0/48 iomem 0xa0000/131072 wsdisplay0 at vga0 mux 1: console (80x25, vt100 emulation), using wskbd0 wsdisplay0: screen 1-5 added (80x25, vt100 emulation) pcppi0 at isa0 port 0x61 midi0 at pcppi0: <PC speaker> spkr0 at pcppi0 npx0 at isa0 port 0xf0/16: using exception 16 pccom0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo fdc0 at isa0 port 0x3f0/6 irq 6 drq 2 fd0 at fdc0 drive 0: 1.44MB 80 cyl, 2 head, 18 sec biomask fbed netmask ffed ttymask ffef pctr: 686-class user-level performance counters enabled mtrr: Pentium Pro MTRR support dkcsum: wd0 matches BIOS drive 0x80 root on wd0a rootdev=0x0 rrootdev=0x300 rawdev=0x302
