howto limit what gets logged in mod_jk.log file

[Mike Curwen]

our mod_jk.log file is 30MB and growing. As far as I can tell, there are 3 types of messages:
[jk_ajp_common.c (1052)]: ERROR sending data to client. Connection aborted or network problems
[jk_ajp_common.c (1303)]: ERROR: Client connection aborted or network problems
Which I understand. Someone clicked 'stop' on the browser.

[jk_ajp_common.c (1011)]: Error sending request body
[jk_ajp_common.c (1309)]: sending request to tomcat failed in send loop. err=0
This one I don't understand, but it's fairly un-common.
But the huge majority of message are the following set of 4 lines:
[jk_ajp_common.c (738)]:
ERROR: can't receive the response message from tomcat, network problems or tomcat is down. err=-1
[jk_ajp_common.c (1137)]:
Error reading reply from tomcat. Tomcat is down or network problems.
[jk_ajp_common.c (1290)]:
ERROR: Receiving from tomcat failed, recoverable operation. err=0
[jk_ajp_common.c (1309)]:
sending request to tomcat failed in send loop. err=0

I've read up a bit, and figured that maxClients in httpd.conf should match maxProcessors in server.xml. So I upped the maxProcessors to match my httpd.conf's 150.

Two things:
1) It seems to have no effect on these messages
2) There is no conceivable way that we have 150 simultaneous requests. We simply do not have the traffic.

What else might be causing these messages, and how do I turn them off?