--On Friday, February 26, 2010 9:46 AM +0100 Peter Mogensen apm@mutex.dk wrote:

Hi,

I see a strange thing in cn=Monitor. Suggestions needed.

I have a huge database, and performance is great as long as olcReadOnly is TRUE. But a soon as I enable writes, the number of Read Waiters are growing, even though there's no or very few Write waiters.

# Read, Waiters, Monitor dn: cn=Read,cn=Waiters,cn=Monitor monitorCounter: 311

# Write, Waiters, Monitor dn: cn=Write,cn=Waiters,cn=Monitor monitorCounter: 0

# Current, Connections, Monitor dn: cn=Current,cn=Connections,cn=Monitor monitorCounter: 210

I have idletime=120 and connections do around 30 reads each before they are retired, but not many writes. Like this:

# Connection 5389, Connections, Monitor dn: cn=Connection 5389,cn=Connections,cn=Monitor monitorConnectionNumber: 5389 monitorConnectionOpsReceived: 32 monitorConnectionOpsExecuting: 0 monitorConnectionOpsPending: 0 monitorConnectionOpsCompleted: 32 monitorConnectionGet: 32 monitorConnectionRead: 32 monitorConnectionWrite: 0

It's slapd 2.4.21, BDB 4.8.26 and back_bdb.

Any hint to what could cause that many read-waiters, but only while writing is enabled and even though there's not that many writes?

It could be a bug in back-monitor...

--Quanah

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Quanah Gibson-Mount Principal Software Engineer Zimbra, Inc -------------------- Zimbra :: the leader in open source messaging and collaboration