Thanks for the suggestion, Ben. I will add a new command line option.
Thanks, Michael On 4/21/15 12:30 PM, "Ben Pfaff" <b...@nicira.com> wrote: > > > What if we add a command line option that >disables logging to the local syslog, instead logging just to the >--syslog-target? > > >> >> >> >> >> >> >> On 4/20/15 12:36 PM, "Ben Pfaff" <b...@nicira.com> wrote: >> >> >After speaking to the author of the current code, it works as it does >> >because of a concern that the connection to the remote syslog might be >> >unreliable, that the remote data is harder to get at, and that it's >> >harder to see it in the context of other messages logged on the local >> >system, so that the redundancy has some value. Michael, do any of >> >these arguments apply to what you're working on? >> > >> >On Wed, Apr 15, 2015 at 09:17:24AM -0700, Ben Pfaff wrote: >> >> Presumably there is a use case for sending to both local syslogd and >>to >> >> a remote UDP server. It is probably even a VMware use case, because >> >> this feature was added by Henry Mai (then a VMware employee), who >>didn't >> >> often contribute to OVS. I guess that he would not have designed it >>to >> >> send to both targets, and documented it to do so, if that was >> >> undesirable. I would not want to break this use case. >> >> >> >> Henry: if it's OK to ask you a question even though you've departed >> >> VMware, can you tell us why --syslog-target sends to both the local >>and >> >> the remote targets, instead of replacing the local target? Thanks! >> >> >> >> On Wed, Apr 15, 2015 at 05:17:35AM +0000, Michael Hu (NSBU) wrote: >> >> > Hi Ben, >> >> > >> >> > Some logger analysis tool has some local agent listening on a >>single >> >>node to collect logs. One of the popular tool called log insight which >> >>uses rsyslogd as local client to listen and transferring log to log >> >>insight server. >> >> > >> >> > Currently syslog() function does not support structured data with >> >>key/value pairs in the log header specified by RFC 5424. >> >> > >> >>>>https://urldefense.proofpoint.com/v2/url?u=https-3A__tools.ietf.org_htm >>>>l_ >> >>>>rfc5424&d=AwIBAg&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=Cj4PPu >>>>e3 >> >>>>W0GyOLVXTqBSOj3Puq_bWcXnUDF91V-EpLY&m=E4Qw3lzvS7sJs2pgUWAt9pCqJQUwTQlVI >>>>Wk >> >>C-5aHETs&s=JrIt7nB_vZmH6vT9LaU_ADT6BI24jLbee2wFAXucW2w&e= >> >> > Log analysis tool uses these header to categorize and filter log >> >>messages. If sending structured data as main log message, it won't be >> >>recognized by the log collector. That's why we have to send raw UDP >> >>packet directly to rsyslogd which contains both structured header and >> >>main log messages. >> >> > >> >> > If using vlog to send udp to rsyslogd by specifying >> >>--syslog-target=127.0.0:514, we would see duplicated messages in >> >>/var/log/syslog as vlog also calls syslog() for the same message. That >> >>is the reason for this patch. >> >> > >> >> > BTW, since this parameter is called syslog-target, do we expect >>user >> >>to either specify this to send udp log message or let vlog call >>syslog() >> >>but not both at the same time? Is there other use case to send UDP >> >>packet and call syslog() at the same time? >> >> > >> >> > Thanks, >> >> > Michael >> >> > >> >> > ________________________________________ >> >> > From: Ben Pfaff <b...@nicira.com> >> >> > Sent: Tuesday, April 14, 2015 9:11 PM >> >> > To: Gurucharan Shetty >> >> > Cc: Michael Hu; ovs-dev >> >> > Subject: Re: [ovs-dev] [PATCH] vlog.c: Avoid duplicating log >>message >> >>in rsyslog if enabling syslog-target >> >> > >> >> > On Fri, Apr 10, 2015 at 07:30:13AM -0700, Gurucharan Shetty wrote: >> >> > > On Thu, Apr 9, 2015 at 8:42 PM, Michael Hu <humich...@nicira.com> >> >>wrote: >> >> > > > Currently if --syslog-target=127.0.0.1:514 is enabled, syslog >> >>would have >> >> > > > duplicated log messages. The fix will not call syslog() if >> >>already having >> >> > > > syslog_fd indicating message is sent through udp. >> >> > > >> >> > > You forgot to add a Signed-off-by. >> >> > > When I 'git am' this patch, I get: >> >> > > Applying: vlog.c: Avoid duplicating log message in rsyslog if >> >>enabling >> >> > > syslog-target >> >> > > fatal: corrupt patch at line 15 >> >> > > >> >> > > I personally think that your patch makes sense. But the >> >>documentation >> >> > > (e.g. 'man ovs-vswitchd') says: >> >> > > >> >> > > --syslog-target=host:port >> >> > > Send syslog messages to UDP port on host, in >> >>addition to the >> >> > > system syslog. The host must be a numerical IP >> >>address, not a >> >> > > hostname. >> >> > > >> >> > > So when this feature was added, I think it was mostly meant for a >> >> > > remote IP address and not local. So your patch breaks the "in >> >> > > addition" part of the current expectation. >> >> > >> >> > I'd like to hear why one would pass --syslog-target=127.0.0:514 at >> >>all. >> >> > Why is this useful, if the system already has a working syslog() >> >> > facility? >> >> > >> >> > Thanks, >> >> > >> >> > Ben. >> _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
