Client connection to MaxDB7.9 is very slow

[Former Member]

Hello,

does any one have an idea why a connection via sqlcli -n hostname -d dbname to the MaxDB (Version 7.9), from remote client is so slow.

I checked that there is no firewall between and traceroute is showing even quick response. It is independent if I use hostname

or IP address. So I guess it is not a network related issue.

Connections to the old environment with MaxDB version 7.6 is fast as usual.
Is there a kind of tracing which I can enable to see what is happening during the first connect?

Any suggestion is welcome.

Kind Regards,

  Werner

[thorsten_zielke]

Hi,

I am not aware of any issue here. Works fine for my test system using 7.9 and 7.6...

You can try MaxDBs 'x_ping' command for further analysis, maybe this helps.

Kind regards,
Thorsten

[Former Member]

Hi Thorsten,

the x_ping shows the following:

[sdb@defrap1060 pgm]$ x_ping -n 10.171.230.170 -d adb1

Pinging adb1 on 10.171.230.170 with 512 bytes of data over a maximum of 10 hops.

Hop  Server
0   XServer
1   ADB1

ADB1: reply time=395us
ADB1: reply time=363us
ADB1: reply time=348us
ADB1: reply time=389us
ADB1: reply time=357us

ADB1: 'UNKNOWN'

Approximate round trip times:
Minimum = 348us, Maximum = 395us, Average = 370us

But from the more faster database it took 18ms, as shown below. But there I got immediately feedback, whereas for the first one it took about 45 seconds until I got feedback.

[sdb@defrap1060 pgm]$ x_ping -n 10.253.1.16 -d adb1

Pinging adb1 on akde6069.de.kaercher.com with 512 bytes of data over a maximum of 10 hops.

Hop  Server
0   XServer
1   ADB1

ADB1: reply time=18 ms
ADB1: reply time=18 ms
ADB1: reply time=17 ms
ADB1: reply time=18 ms
ADB1: reply time=18 ms

ADB1: 'KERNEL    7.6.03   BUILD 015-123-173-107'

Approximate round trip times:
Minimum = 17ms, Maximum = 18ms, Average = 18ms

So I guess it is more a initial thing at a lower network level.

KG,

Werner

[thorsten_zielke]

Hi Werner,

if I understand you correct, then the 'x_ping' to 10.171.230.170 hangs for about 45 seconds and only then delivers the result?
If so, it may very well be a problem with the reverse DNS lookup in your network to that server 10.171.230.170. The involved MaxDB 'x_server' definitely uses reverse DNS lookup (which means that the given IP address is used to look up the server name).

To verify if this is indeed the problem cause you could try to start the 'x_server' on the database server 7.9 with the following options:
1. go to database server 7.9 (10.171.230.170)

2. execute 'x_server stop'

3. Start a new x_server without DNS lookup using 'serv directly (which normally gets called through x_server) -> 'serv -F'

Hope this still works via the 'serv -F' command; Then, just return to the client server and retry the 'x_ping' / 'sqlcli' against the 7.9 database...

Thorsten