An exciting change landed in the development version of Prometheus recently, making PromQL arithmetic expressions in time durations a standard feature instead of an experimental one. For me, durationarithmetic expressions by themselves aren't the truly interestingpart. What's really exciting is that as part of this change,Prometheus has added some new PromQL functions, especially step() .

(Although step() is gated behind an 'experimental PromQLfunctions' feature flag today, it will be made available as a standardfunction as part of

Over on the Fediverse, I had a little exchange recently:

[other person in a conversation]: I still haven’t forgiven Sun forNFS. No I’m not bitter.

@cks : It couldhave been worse, Sun could have stuck with nd.

What I was referencing in my post is a now obscurepiece of cursed knowledge that I'm happy to share with you today.

Sun's workstations could boot without a local disk from very early on( because that made them cheaper,

Suppose, not hypothetically , that you have asituation where there's a number of distinct hosts backing some Gitrepository, such as all of the IP addresses ofhttps.git.savannah.gnu.org, and one or more of them seem to beoutdated or not working right. As far as I know, Git itself providesvery few tools to examine or control which host the fetching processuses; the best option ' git fetch ' has is to select only IPv4 orIPv6 hosts (well

Suppose that you (I) write an Apache configuration stanza to make somesettings conditional on the module that they're from, so you canenable and disable the module without blowing up your web serverconfiguration (or having to edit it). Your version looks like this:

  QS_LocRequestLimitMatch "^...$" 1000  QS_SrvMaxConnPerIP 8 100

Unfortunately, this stanza isn't doing what you (I) think it

Today I shared a brief war story on the Fediverse :

Today's new and exciting failure mode for a DHCP server handing outleases to dynamic clients: have something on your network thatanswers pings for absolutely every IP address (yes, it was broken).The ISC DHCP server pings what it thinks is a free IP before handingit out (to be sure), so if something answers all of those pings youhave no 'free' IPs on your network and no one gets a dynamic IP.

(

Suppose, not entirely hypothetically, that you're installing a serverwith two network ports and during the (Linux) installation, a thirdnetwork device shows up with a funny name like 'enp1s0f4u1u2c2', whichis a USB Ethernet device (despite you not having any such thingplugged in to the server's USB ports). To your further surprise, yourserver installer can even lease a DHCP IP on this interface, say"169.

It started with a discovery about my access to the official Emacsrepository :

This is my face when my home desktop appears to be persistentlytalking to one instance of https.git.savannah.gnu.org that is manydays out of date and out of sync on the GNU Emacs git repository.Yes, I know, volunteer organization, but how do you eventroubleshoot that? At this rate I'm going to have to switch to theGithub mirror even though the thought makes me spit reflexively.

(By

In a comment on my entry about how sometimes it's the networkthat's the problem , I was asked whatnetworking workstations typically have on our networks (and if westill use 100 MBit for low speed things). The simple answer is thatit's somewhat mixed but mostly 1G Ethernet, often with 1G uplinksfrom the switches that the office network jacks are connected to.But there's some stories involved.

As a university department, we have been in our current buildings

Suppose, not hypothetically, that you have a web server that's usingas much of your server's bandwidth as it can get and you would like it to useless bandwidth than that, so that you can get a word in edgewise (forbackups, for example) or just because you don't feel like donating1/10th of your outgoing bandwidth in apparent perpetuity to people whoshould be building local caches. There are various ways you might dothis, for example using FreeBSD pf