| Cannot connect through single client access name scan after 1st node pubic cable is plugged off [message #643038] |
Sat, 26 September 2015 09:21  |
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juniordbanewbie
Messages: 250
Registered: April 2014
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Senior Member |
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Dear all,
I pull out a public cable from imdb01, expecting that imdb01-vip will failover and all db connections to switch to imdb02
Here's my observation:
oracle@imdb02:~> srvctl status vip -n imdb01
VIP imdb01-vip is enabled
VIP imdb01-vip is not running
Detailed state on node imdb02:FAILED OVER
oracle@imdb02:~> srvctl status vip -n imdb02
VIP imdb02-vip is enabled
VIP imdb02-vip is running on node: imdb02
I did a double confirmation through ifconfig:
oracle@imdb02:~> /sbin/ifconfig
eth0 Link encap:Ethernet HWaddr 40:F2:E9:2A:D3:02
inet addr:192.168.56.62 Bcast:192.168.56.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:7123371 errors:6 dropped:7365 overruns:0 frame:4
TX packets:4027265 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1315536340 (1254.5 Mb) TX bytes:779661543 (743.5 Mb)
Memory:90580000-905a0000
eth0:1 Link encap:Ethernet HWaddr 40:F2:E9:2A:D3:02
inet addr:192.168.56.65 Bcast:192.168.56.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Memory:90580000-905a0000
eth0:2 Link encap:Ethernet HWaddr 40:F2:E9:2A:D3:02
inet addr:192.168.56.67 Bcast:192.168.56.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Memory:90580000-905a0000
eth0:3 Link encap:Ethernet HWaddr 40:F2:E9:2A:D3:02
inet addr:192.168.56.66 Bcast:192.168.56.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Memory:90580000-905a0000
eth0:4 Link encap:Ethernet HWaddr 40:F2:E9:2A:D3:02
inet addr:192.168.56.64 Bcast:192.168.56.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Memory:90580000-905a0000
eth0:5 Link encap:Ethernet HWaddr 40:F2:E9:2A:D3:02
inet addr:192.168.56.63 Bcast:192.168.56.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Memory:90580000-905a0000
192.168.56.63 being imdb01-vip is indeed failover
The above is expected:
however I can't connect to db through single client access name:
sys@imdb-scan/ORCLSE> conn sys/*********@imdb-scan/ORCLSE as sysdba
ERROR:
ORA-12502: TNS:listener received no CONNECT_DATA from client
warning: You are no longer connected to ORACLE
Although I can connect through imdb02-vip. I also don't understand why there's still db connections through first instance
conn sys/*********@imdb02-vip/ORCLSE as sysdba
connected
SYS@imdb02-vip/ORCLSE> SELECT sys_context('userenv','sid') FROM dual;
SYS_CONTEXT('USERENV','INSTANCE')
--------------------------------------------------------------------------------
2
SYS@imdb-scan/ORCLSE>select inst_id,count(0) from gv$session where username is not
null AND type != 'BACKGROUND' GROUP BY inst_id ORDER BY inst_id;
INST_ID COUNT(0)
---------- ----------
1 20
2 17
I get the following from the listener log:
grep 'TNS-12502' /u01/app/grid/diag/tnslsnr/imdb02/listener/trace/listener.log
TNS-12502: TNS:listener received no CONNECT_DATA from client
I also cannot grep anything useful in listener_scan logs
I've check the listener status
grid@imdb02:~> lsnrctl status listener_scan1
LSNRCTL for Linux: Version 11.2.0.3.0 - Production on 25-SEP-2015 12:03:53
Copyright (c) 1991, 2011, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER_SCAN1)))
STATUS of the LISTENER
------------------------
Alias LISTENER_SCAN1
Version TNSLSNR for Linux: Version 11.2.0.3.0 - Production
Start Date 25-SEP-2015 11:33:06
Uptime 0 days 0 hr. 30 min. 47 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/11.2.0.3/grid/network/admin/listener.ora
Listener Log File /u01/app/11.2.0.3/grid/log/diag/tnslsnr/imdb02/listene r_scan1/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=LISTENER_SCAN1)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.56.67)(PORT=1521)))
Services Summary...
Service "ORCLSE" has 1 instance(s).
Instance "ORCLSE2", status READY, has 1 handler(s) for this service...
I've followed MOS 975457.1 How to Troubleshoot Connectivity Issue with 11gR2 SCAN Name, but still could not understand what went wrong. nearest forum posting is https://community.oracle.com/thread/1009237 but then again that post is concerned about vip not able to failover, whereas my case is vip failover but connection through SCAN fails and there's still db connections to the disconnected instance.
So would appreciate if someone could enlighten me on these two issues:
why cannot connect through scan. how to resolve this?
why there still db connections through the disconnected node
What makes the issue with SCAN challenging is that if I repeat the test again, sometimes it can connect, sometimes it cannot connect.
Many many thanks in advance!
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| Re: Cannot connect through single client access name scan after 1st node pubic cable is plugged off [message #643040 is a reply to message #643038] |
Sat, 26 September 2015 09:52  |
John Watson
Messages: 8976
Registered: January 2010
Location: Global Village
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Senior Member |
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Your questions Quote:why cannot connect through scan. how to resolve this?
why there still db connections through the disconnected node First, you may be having issues with DNS and ARP and routing tables and caching. I am not a networking specialist, but I do know that if you have address caches enabled you may be trying to connect to what is now a useless MAC address.
Second, I would think that those sessions will (eventually) die. It will take a while for the server processes to realize that their user process has disconnected.
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