News for hackers. Stuff that matters.
Re:A Google Cloud support engineer solves a tough DNS case by zimbatm on Tuesday May 19, 2020 @02:15PM (#23238143)
Did you read the article?

The customer had set `net.core.rmem_default = 2147483647` on purpose. Which exposed a Kernel bug. The whole herd would be having the same issue.

Re:A Google Cloud support engineer solves a tough DNS case by brightball on Tuesday May 19, 2020 @02:26PM (#23238276)
I think what he's trying to suggest is that the customer may have been able to isolate the issue faster by walking through the provisioning settings for the machine to identify core changes.

The bug report resulted in a core fix, which is a better result than if the customer had fixed it themselves of course.

Re:A Google Cloud support engineer solves a tough DNS case by anonymousisme on Tuesday May 19, 2020 @03:04PM (#23238775)
Also, it was very nice of Google to follow up and submit the patch to LKML. IMHO this goes beyond the scope of their role. They could have taken a more selfish approach and accepted the bug as "normal" behavior, and advised their customer to not configure the buffer to such an enormous size.
Re:A Google Cloud support engineer solves a tough DNS case by lalos on Tuesday May 19, 2020 @03:19PM (#23238942)
Any decent engineer would smile at the fact that they just found a bug in this type of open source stack and happily submit it. Feel this is more of a side effect of individual behavior rather than company policy.
Re:A Google Cloud support engineer solves a tough DNS case by calvinmorrison on Tuesday May 19, 2020 @03:52PM (#23239349)
until you hit something like "bug reports should be subitted to here, not there and filled out with appropriate information, matching triplicate documents and make sure to CC the grand puba, also CLOSED-WONTFIX" enough times and you just stop submitting requests.
Re:A Google Cloud support engineer solves a tough DNS case by saagarjha on Tuesday May 19, 2020 @05:09PM (#23240220)
Unfortunately, not every engineer has an employer that would let them do this…
Re:A Google Cloud support engineer solves a tough DNS case by mcguire on Tuesday May 19, 2020 @03:42PM (#23239237)
"Professional responsibility", if nothing else.
Re:A Google Cloud support engineer solves a tough DNS case by indigodaddy on Tuesday May 19, 2020 @03:08PM (#23238820)
Was thinking the exact same thought as I finished up the article...
Re:A Google Cloud support engineer solves a tough DNS case by ibejoeb on Tuesday May 19, 2020 @02:37PM (#23238418)
I really want to know if the telemetrics (or whatever the thing was) pushed enough packets to actually warrant the config. Setting something to the max sounds like preopt to me. This must be a truly exceptional condition if it actually remained undiscovered since linux 3.
Re:A Google Cloud support engineer solves a tough DNS case by sleepydog on Tuesday May 19, 2020 @06:48PM (#23241219)
I can't think of anything that would warrant a 2GB receive buffer. The buffer should be sized so that the receiving program has a reasonable amount of time to drain it before it becomes full. A large skylake VM in GCP can do 32 Gbps (lowercase b), so assuming worst conditions, a 2GB receive buffer would give the receiver 500ms to call recv(), which is a huge amount of time for something that should take microseconds, especially in the context of a client.

Even if there was a specialized server that needed such a large receive buffer, it doesn't make sense to set the system-wide default so high.