Checking backend server status & issues

1. Check if the server health-check is ON;

Check current server status with diagnose:

diagnose policy backend back-end server list <Server Pool>

FortiWeb # diagnose policy back-end server list root. SP_01

policy(SP_01)

server-pool(RS_01) sp_id(14718170086418654778):

total = 2

server[0]

server table id: 1

server random id: 14419242131006337869

ip: x.x.x.x

port: 80

alive:

1

session: 0

idle: 0

status: 1

backup: 0

server[1]

server table id: 2

server random id: 3111587693898389030

ip: y.y.y.y

port: 8080

alive:

0

session: 0

idle: 0

status: 1

backup: 0

alive server 1:

server[0]

alive backup server 0:

2. Check event logs for history status if server-pool health check is ON: Add Filter > Action > Check-Resource. You’ll see like this:

   Physical Server 1 [3.89.138.120:80] in server pool RS_01 status change from up to down

3. If server-pool health check is OFF or you doubt the back-end server status is not stable, you may use curl to visit the back-end server (IP or FQDN) under FortiWeb root:

   /# curl -I http://x.x.x.x/

   /# curl -I https://x.x.x.x/

   /# curl -I --recursive https://x.x.x.x/

   Note: Using “execute telnettest x.x.x.x:80” under FortiWeb shell or “telnet x.x.x.x:80” may not work well because the HTTP headers cannot be fully sent and parsed.
4. Check if the request might be limited by “Connection Limit”.