Date: Mon, 24 Feb 2003 17:42:52 +0100 From: Alexander Langer <alex@big.endian.de> To: hackers@FreeBSD.org Subject: mysql endless loops Message-ID: <20030224164252.GD33820@fump.kawo2.rwth-aachen.de>
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Hi! A known bug with MySQL 3.x is that it sometimes enters a 100% cpu usage loop if you stress it too much (I can repeat this every 2-3 weeks). I just attached a ktrace, and it shows this: 57486 mysqld CALL poll(0x8382000,0x4,0xb8c) 57486 mysqld RET poll 1 57486 mysqld CALL gettimeofday(0x283fddec,0) 57486 mysqld RET gettimeofday 0 57486 mysqld CALL poll(0x8382000,0x4,0xb8c) 57486 mysqld RET poll 1 57486 mysqld CALL gettimeofday(0x283fddec,0) 57486 mysqld RET gettimeofday 0 57486 mysqld CALL poll(0x8382000,0x4,0xb8c) 57486 mysqld RET poll 1 57486 mysqld CALL gettimeofday(0x283fddec,0) 57486 mysqld RET gettimeofday 0 57486 mysqld CALL poll(0x8382000,0x4,0xb8c) 57486 mysqld RET poll 1 57486 mysqld CALL gettimeofday(0x283fddec,0) 57486 mysqld RET gettimeofday 0 57486 mysqld CALL poll(0x8382000,0x4,0xb8c) 57486 mysqld RET poll 1 57486 mysqld CALL gettimeofday(0x283fddec,0) 57486 mysqld RET gettimeofday 0 57486 mysqld CALL poll(0x8382000,0x4,0xb8c) 57486 mysqld RET poll 1 57486 mysqld CALL gettimeofday(0x283fddec,0) 57486 mysqld RET gettimeofday 0 57486 mysqld CALL poll(0x8382000,0x4,0xb8c) 57486 mysqld RET poll 1 57486 mysqld CALL gettimeofday(0x283fddec,0) 57486 mysqld RET gettimeofday 0 57486 mysqld CALL poll(0x8382000,0x4,0xb8c) 57486 mysqld RET poll 1 57486 mysqld CALL gettimeofday(0x283fddec,0) 57486 mysqld RET gettimeofday 0 57486 mysqld CALL poll(0x8382000,0x4,0xb8c) 57486 mysqld RET poll 1 57486 mysqld CALL gettimeofday(0x283fddec,0) 57486 mysqld RET gettimeofday 0 57486 mysqld CALL poll(0x8382000,0x4,0xb8c) 57486 mysqld RET poll 1 ... (approx. 80 MB of these lines, then I killed the process). It seem the thread handling is broken for mysql (this gettimeofday happens in the "while (select_thread_in_use)" in mysqld.cc I believe. Anyways, I'm going to try mysql 4.0 now, maybe someone can use the information above. Alex To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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