mysql kresuje

[Miroslav Lachman]

Martin Zdrazil wrote:
> mysqld got signal 10;
> 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=8388600
> read_buffer_size=131072
> max_used_connections=101
> max_connections=100
> threads_connected=55
> It is possible that mysqld could use up to
> key_buffer_size + (read_buffer_size + sort_buffer_size)*max_connections =
> 225791 K
> bytes of memory
> Hope that's ok; if not, decrease some variables in the equation.

A zkousel jste si uz spocitat, kolik pameti ta vase MySQL v extremni 
situaci potrebuje? Ma ji tolik opravdu povoleno?
Ja tuhle stejnou chybu vidal u MySQL 4.1.x v pripade, kdy jsem v 
/boot/loader.conf mel povoleno min pameti, nez kolik MySQL opravdu 
chtela "sezrat". Takze podle poskytnuteho vzorce pro vypocet:
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_connections
jsem spocital, kolik ji je potreba, pripocetl nejakou rezervu a to 
nastavil v /boot/loader.conf. Od te doby jsem nevidel ani jeden pad 
MySQL na tech strojich, kterych se to predtim tykalo. A zatizeni neni 
zrovna nejmensi (i kdyz po vyladeni aplikace uz neni tak vysoke, jako driv)

# mysqladmin status
Uptime: 7313976  Threads: 3  Questions: 2159020044  Slow queries: 100658 
  Opens: 4446  Flush tables: 7  Open tables: 946  Queries per second 
avg: 295.191

Uptime daemona je 84 dnu, drive to ve spickach delalo az 3000 queries / 
s, navic je to Master pro replikaci, takze se jeste vse uklada do binlogu.

> mysql-server-5.0.16

Petkova rada MySQL je z meho pohledu "zlo", protoze tam za poslednich 
par verzi udelali natolik zasadni zmeny ohledne interniho fungovani 
triggeru, ze temer po kazdem upgrade triggery prestanou fungovat, nebo 
zmizi, ale nedaji se ani znovu vytvorit, protoze MySQL hlasi, ze jiz 
existuji, jenze nejdou ani dropnout, protoze MySQL zahlasi, ze 
neexistuji. Musi se pak dropnout cela databaze a znovu vytvorit. Za 
posledni 4 mesice se to na serveru jednoho klienta stalo snad uz trikrat.

Miroslav Lachman