Hi Fredrik, Thanks your reply.
2014-01-07 17:26 időpontban Fredrik Björk ezt írta: > I assume the SNR needs to be calculated at that specific point in > time and > that can take a little while. RX power is probably easier for the > modem to > keep track of internally. No, reading the SNR oid reply time is ok. But: Reading the RX pwr oid is too slow. I tried several oids (from the modem) (like TX PWR, sysDescr, etc..) and every case i get the result in normal reply time, only query the RX pwr is significantly slower.. :( > I tried 100 reads using a bash script: > > time for (( i=0 ; i-100 ; i++ )) ; do time snmpget -v2c -c public > 172.19.11.225 1.3.6.1.2.1.10.127.1.1.4.1.5.3 ; done > real 0m7.656s > user 0m3.852s > sys 0m0.384s > > Here, again, SNR takes a lot longer to report: > > time for (( i=0 ; i-100 ; i++ )) ; do time snmpget -v2c -c public > 172.19.11.225 1.3.6.1.2.1.10.127.1.1.1.1.6.3 ; done > > real 0m30.375s > user 0m3.916s > sys 0m0.400s > > This particular modem is a Compal CV6181ES running an old FW image > 3.0.0.0-GA-01-SH. EPC3212 modems also respond slower whne queried for > SNR. > I guess we have to blame Broadcom for this :) > > EPC3212 response times (script as above) > > real 0m9.023s > user 0m3.860s > sys 0m0.452s > > real 1m16.681s > user 0m3.772s > sys 0m0.504s We use mainly Thomson modems, and few Cisco. > One way to reduce polling time is to send multiple queries at the > same > time and let the script sort out the different answers: > > snmpget 172.19.14.195 -v2c -c public 1.3.6.1.2.1.10.127.1.1.1.1.6.3 > 1.3.6.1.2.1.10.127.1.1.4.1.5.3 Yes, i use one query and multiple oid, as you say, but the result is the same. > This way, I managed to get the EPC3212 to respond in 1m15 sec for > both > parameters. This way you save the overhead of asking two questions > and the > modem compiling two answers, but the SNR query is still time > consuming. > > > What are you trying to acheive? You might get past the delay by > having a > background program continously read the SNR from the modems and > adding/updating the data to a database (Postgres/MySQL/...) and just > read > from there whenever you need. That will give you the latest data > possible > at an instant. I develop a docsis NMS system, and i need this docsis data from every modems, then i save that data to the modem rrd files, and later i show in graf. So in this time we have ~3500 modems, and i would like max. total polling time: ~1.5min. (no more!) > /Fredrik -- szpal ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Net-snmp-users mailing list [email protected] Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
