Collect the Apache client count in check_health.

The Apache process count is roughly the Apache client count. Start collecting
the data, and the next step is for test to pick the devserver with least Apache
client count. That helps to monitor/balance the devserver load.

TEST=run devserver locally, and curl http://localhost:8082/check_health

Change-Id: I9e00ad64955da0237c80e1a0e9cf09103004c522
Commit-Ready: Dan Shi <>
Tested-by: Dan Shi <>
Reviewed-by: Fang Deng <>
1 file changed