Gilbert, > Hi Steve, > > So, a funny thing happened to me yesterday, and not "ha ha" funny: > an SCCM Society of Critical Care Medicine? System Center Configuration Manager? > server was pegged with 800 mb/sec of downloads on campus, > and as a result, for three hours, I was down. Then, when they > shut it off to stop the problem, as it was jamming the DNS > servers as well... > > I got a flood of data. An hour's worth of radar: Level 2, 3 > and then NGRID, HRS, yadda, yadda. So, for 3 hours your LDM wasn't receiving data because the campus network was clogged by other downloads? > And one of our campus IT professionals was NOT happy, nor was > one of our ISP's Syndeo. They flagged it as a DDOS due to the > high amounts of traffic from multiple different servers inbound > and outbound, being a relay...and so they blocked me. That was rather draconian. The LDM uses TCP, which plays nice with others and automatically adjusts to available bandwidth -- using less if the network is congested and more as the network becomes uncongested. > I'm unblocked now, but here's why this happened: Weather3.admin.niu.edu > used to be a server from 2005. Now it's from 2014, has 8 Core i7 > processors, a 4620 (not sure I remember correctly) motherboard, 1600 GHZ > RAM, etc. It's not slow. In 7 years, it will be. :-) > > So, instead of taking up to 15 minutes for the LDM to catch up and > retransmit the data with the old weather3, it took SECONDS > with the new one. This is a very good thing, and potentially a > bad thing. > > Is there any way to have a feature "throttle" the LDM to some degree so > that it doesn't hit panic alarms when outages like this happen? With > gigabit comnnections and fast servers, this may be a problem > in the future, causing false DDOS alarms to ISP's and such. The LDM doesn't have the capability of throttling itself -- nor is one planned. If you feel this is a needed feature, then I encourage you to add it to the "Issues" list for the LDM at its GitHub repository <https://www.github.com/Unidata/ldm>. One might be able to use the tc(1) utility to impose a limit on TCP connections involving port 388. Would you please investigate this before adding to the LDM's "Issues" page. Thanks. > Gilbert Regards, Steve Emmerson Ticket Details =================== Ticket ID: BRZ-289323 Department: Support LDM Priority: Normal Status: Closed
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