On 10/17/14 5:38 PM, Anthony Biacco wrote: > I just started running pool 2.2 alongside dbcp 2.0.1 in tomcat 7 against > mysql. > > I noticed a situation while running the idle evictor where there's a time > during eviction where the number of connections drops below the value set > for minIdle, so in theory if all connections were idle for > minEvictableIdleTimeMillis, i could have no free connections. > After the eviction, connections seem to be created back up to minIdle. > > I expected it to only evict down to the minIdle value, not evict all > eligible idle connections and then recreate up to minIdle. > The way i'm viewing the number of connections is through mysql's "show full > processlist" command. > Is what i'm describing possible or am I missing something?
Yes, this is possible. When evicting idle instances due to minEvictableIdleTimeMillis exceeded, the evictor does not take into account the number of idle instances remaining in the pool and it performs the evict, ensure min idle actions in sequence. If you want to avoid the destroy / recreate scenario, you can use softMinEvictableIdleTimeMillis instead. > If it is possible, couldn't this cause the resource to become unavailable > in the time between destruction and recreation? I am not sure what you mean here. This could lead to the idle instance count hitting zero, but client threads will still get served as long as maxTotal is not exceeded. Client threads will create instances to serve requests when the pool is empty, as long as there is capacity to do so, and evictor destroy actions immediately create capacity. Borrowers may have to incur makeObject (create physical connection in DBCP case) latency, but they will get served. Phil > > Here's my config: > initialSize="15" > minIdle="15" > maxIdle="100" > maxTotal="200" > maxWaitMillis="4000" > defaultQueryTimeout="20" > testOnBorrow="true" > testWhileIdle="true" > blockWhenExhausted="true" > numTestsPerEvictionRun="50" > timeBetweenEvictionRunsMillis="120000" > minEvictableIdleTimeMillis="119000" > validationQuery="SELECT 1" > validationQueryTimeout="2" > removeAbandoned="true" > removeAbandonedOnBorrow="true" > removeAbandonedTimeout="60" > logAbandoned="true" > > Thanks, > > -Tony > --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@commons.apache.org For additional commands, e-mail: user-h...@commons.apache.org
