Sunday, July 17, 2005

PostgresSQL

On the Apple iChat Discussion Pages.
Kevin Woon reported this:

You don't actually need to kill PostgreSQL to be able to run iChat. I did some experimenting and found that if you reduce the number of shared-buffers. I had started with 300, but reduced it to 75. After I did that everything worked fine.



And Kaan Erdener replied with:

Ok, I managed to get my iSight working again with iChat while leaving postgres running. Here's what I did.

Before I get started, I'm running postgres 8.0.1 on OS X 10.4.1. My postgresql.conf shows these default values for max_connections and shared_buffers:

max_connections = 40
shared_buffers = 200 # min 16, at least max_connections*2, 8KB each

So, I'm not sure where you saw a value of 300. Was it somewhere else besides postgresql.conf? Or are you running a different version of Postgres? Something else?

I tried descreasing shared_buffers to 80 (the smallest value allowed following the math rule of max_connections*2), but iChat still failed on video chats. This was logged to console output:

2005-07-17 06:37:13.894 iChat[8259] WARNING: Freeze-frame failed: couldn't get local buffer for layer Local!

When I decreased both max_connections and shared_buffers, as below, I found that I am now able to leave postgres running and use iChat with iSight for video chats:

max_connections = 20
shared_buffers = 40 # min 16, at least max_connections*2, 8KB each

Kaan


This might help other with the Postgres problem.

Ralph

3 comments:

Ralph Johns said...

Glad to hear it helped.

Evan Corbett said...

I would like to say a Huge Thank You for posting this info.

It totally solved my problem, and i never would have thought about these two things being possibly connected.

I worked with Apple tech support yesterday for several hours trying to diagnose, and had reached the unfortunate point of having them siggest re-installing the OS as the only option left.

This of course would not have fixed the problem either.

Works like a charm now though.

Again, Thanks!

Evan Corbett
Cincinnati, Ohio, US

U R Cool

Ralph Johns said...

Hu Evan,

Glad it helped.

Ralph