topic Re: LASR service not starting after Red Hat Upgrade in SAS Visual Analytics

LASR service not starting after Red Hat Upgrade

LucianoMachado — Thu, 24 Aug 2017 01:36:04 GMT

After the Red Hat patch RHEL 7.4 our Linux Boxes, the LASR Server stopped working and wouldn't come up.

ERROR: A connection to the LASR Analytic Server on 'xxxxxxx.yyyy.zzzz', port 10011, could not be made. Make sure that the

host and port are correctly specified, that you are attempting to connect to a LASR Analytic Server of the correct vintage,

and that the server is still running.

ERROR: Libref LASRTEST is not assigned.

ERROR: Error in the LIBNAME statement.

ERROR: Could not start LASR server. Processing cancelled.

In this security patch some ciphers and algorithms were deprecated in the openSSH, causing some SSH Clients to fail to authenticate.

SAS LASR uses its own ssh (tkssh) client to communicate with other nodes

[/sasbin/SASFoundation/9.4/dbcs/utilities/bin]
 ./tkssh worker01
FATAL ERROR: expected key exchange group packet from server

Re: LASR service not starting after Red Hat Upgrade

LucianoMachado — Thu, 24 Aug 2017 01:40:48 GMT

To fix the issue it is necessary to tell SAS to use the OS ssh Client, by changing sasv9_local.cfg adding the following

-SET GRIDRSHCOMMAND "/usr/bin/ssh -q -o StrictHostKeyChecking=no"

[/sasbin/SASFoundation/9.4]
$ vi sasv9_local.cfg
-MEMSIZE 128G
-SORTSIZE 64G
-BUFSIZE 64K
-UBUFSIZE 64K
-IBUFSIZE 32767
-BUFNO 10
-UBUFNO 10
-IBUFNO 10
-ALIGNSASIOFILES
-SET GRIDRSHCOMMAND "/usr/bin/ssh -q -o StrictHostKeyChecking=no"

Re: LASR service not starting after Red Hat Upgrade

alexal — Thu, 24 Aug 2017 02:40:12 GMT

@LucianoMachado,

The root cause of this problem is that TKSSH is not compatible with OpenSSH that ships with RHEL 7.4. You have to use an external SSH client as you said above. I've found this problem almost immediately after the release of RHEL 7.4.