Analysis of slow start-up of monitoring

If you perform the listening startup operation, you will hang up for a period of time, and finally the listening starts successfully [oracle@sky-oel7 ~] $lsnrctl start.

Connecting to (DESCRIPTION= (ADDRESS= (PROTOCOL=TCP) (HOST=sky-oel7) (PORT=1521)) STATUS of the LISTENER-Alias LISTENER Version TNSLSNR for Linux: Version 12.1.0.2.0-Production Start Date 12-JAN-2016 16:42:57 Uptime 0 days 0 hr. 0 min. 40 sec

It takes 40 seconds to start.

Specify a log level of 16 [oracle@sky-oel7 trace] $cat / oracle/app/oracle/product/12.1.0/dbhome_1/network/admin/listener.ora # listener.ora Network Configuration File: / oracle/app/oracle/product/12.1.0/dbhome_1/network/admin/listener.ora # Generated by Oracle configuration tools.

LISTENER = (DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP) (HOST = sky-oel7) (PORT = 1521)))

TRACE_LEVEL_LISTENER=16

Restart the listener, log [oracle@sky-oel7 trace] $tail-f listener.log

Log messages written to / oracle/app/oracle/diag/tnslsnr/sky-oel7/listener/alert/log.xml Trace information written to / oracle/app/oracle/diag/tnslsnr/sky-oel7/listener/trace/ora_4179_140717186082304.trc Trace level is currently 16

Started with pid=4179 Listening on: (DESCRIPTION= (ADDRESS= (PROTOCOL=tcp) (HOST=sky-oel7) (PORT=1521)

TIMESTAMP * CONNECT DATA [* PROTOCOL INFO] * EVENT [* SID] * RETURN CODE WARNING: Subscription for node down event still pending 12-JAN-2016 16:10:14 * (CONNECT_DATA= (CID= (PROGRAM=) (HOST=sky-oel7) (USER=oracle)) (COMMAND=status) (ARGUMENTS=64) (SERVICE=LISTENER) (VERSION=202375680)) * status * 0

[oracle@sky-oel7 admin] $vi / oracle/app/oracle/diag/tnslsnr/sky-oel7/listener/trace/ora_4179_140717186082304.trc

2016-01-12 16 rime 09 purl 34.211259: nttcnp:binding an address to a socket. 2016-01-12 16 09 purl 34.211275: nttcnp:listening on a bound socket. 2016-01-12 16 nttcnp:exit 09 nttcnp:exit 34.211324: snlinGetAddrInfo:getaddrinfo () failed with error-3 2016-01-12 1640 14. 256096: snlinGetAddrInfo:getaddrinfo () failed with error-1-12 2016-01-12 16 16 purl 1014. 256193: snlinGetAddrInfo:exit 2016-01-12 Exit 2016-01-12 16 10 14. 256241: nsopen:transport is open 2016-01-12 16 14. 25 6261: nsoptions:entry

There is no more information available.

Analyze the process startup information through strace [oracle@sky-oel7 ~] $strace-f-t-o ~ / listener.trc lsnrctl start

View strace log information 5042 16:42:57 socket (PF_INET, SOCK_DGRAM | SOCK_NONBLOCK, IPPROTO_IP) = 13 5042 16:42:57 connect (13, {sa_family=AF_INET, sin_port=htons (53), sin_addr=inet_addr ("172.24.97.1")}, 16) = 0 5042 16:42:57 poll ([{fd=13, events=POLLOUT}], 1, 0) = 1 ([{fd=13, revents=POLLOUT}]) 5042 16:42:57 sendto (13) ":\ 26\ 1\ 0\ 0\ 0\ 0\ 0\ 0\ 0\ 0\ 0\ 0\ 0\ 10sky-oel7\ tworkgroup\ 0", 36, MSG_NOSIGNAL, NULL, 0) = 36 5042 16:42:57 poll ([{fd=13, events=POLLIN}], 1, 5000) = 0 (Timeout)

5042 16:43:02 socket (PF_INET, SOCK_DGRAM | SOCK_NONBLOCK, IPPROTO_IP) = 14 5042 16:43:02 connect (14, {sa_family=AF_INET, sin_port=htons (53), sin_addr=inet_addr ("192.168.191.1")}, 16) = 0 5042 16:43:02 poll ([{fd=14, events=POLLOUT}], 1,0) = 1 ([{fd=14, revents=POLLOUT}]) 5042 16:43:02 sendto (14) ":\ 26\ 1\ 0\ 0\ 0\ 0\ 0\ 0\ 0\ 0\ 0\ 0\ 0\ 10sky-oel7\ tworkgroup\ 0", 36, MSG_NOSIGNAL, NULL, 0) = 36 5042 16:43:02 poll ([{fd=14, events=POLLIN}], 1, 5000) = 0 (Timeout)

The above information shows that the network timeout is caused by the failure of address resolution.

The address information can be found in [root@sky-oel7 ~] # cat / etc/resolv.conf # Generated by NetworkManager search workgroup nameserver 172.24.97.1 nameserver 192.168.191.1 through the DNS configuration file

After blocking these addresses, listener starts normally.