bash – finding files which have one of parent folders with a very specific name, and contain specific sub string
and to compress all of the files into single tar archive:
unimportant
play.pl mobile – 100GB for a month for 5pln
play.pl seems to have never ending promotion where you get 100GB of data traffic for a month when you buy a new starter and activate bonus package. here’s what i do to activate it [ every 30 days ]: buy play-as-you-go sim card e.g. in Zabka convenience store – Play odNowa for 5PLN, register the ... Read More
.net core under linux throws “The remote certificate is invalid because of errors in the certificate chain: NotTimeValid” when communicating with HTTPS server having letsencrypt cert
i’ve stumbled on an issue – simple .net core code using HttpWebRequest failed to communicate with any server that had lets encrypt cert. no matter if the server used new or old certificate chain – i was getting: at the same time curl or wget could communicate with the same site without issues. i’ve tried ... Read More
manual and service manual for LG F4J6TG0W washing and drying machine
maybe it’ll be useful for someone. instrukcja oraz instrukcja seriwsowa do pralko-suszarki LG F4J6TG0W service manual – LG-F4J6TG0W-LG_directdrive_8-145881-2.pdf, user instruction mfl69739861rev4pdf-en.pdf MFL70561437-EN
intellij freezing on startup + putty routinely failing to bind to ports used for ssh tunneling
for the past few weeks i was plagued by putty randomly failing to bind to ports used for ssh tunneling giving me in its log “forwarding failed: Network error: Permission denied” today my intellij failed to launch – it was freezing on the splash screen, C:\Users\xxxxxxxxxxxx\AppData\Local\JetBrains\IdeaIC2021.2\log\log.log had: that brought me to https://youtrack.jetbrains.com/issue/IDEA-238995 and workaroudn described ... Read More
crude way to restore postgresql database dump to table with a different name
i needed to restore specific table, backed up via pg_dump, to the same database / schema but under different name. that’s what i’ve done pv dump.zstd|pzstd -dc - |sed 's/name_of_original_table/name_of_renamed_table/g'|su - postgres -c 'psql dbname' this only works if all constrains / indices have in their name name of the original table.
booting KVM VM from an iso image
let’s say you have a vm, maybe with debian. and that vm stopped booting, maybe because of grub corruption. what do you do? add under devices – for pc-i440fx arch: and for pc-q35-3.1: then in the os section change boot from dev=’hd’ to dev=’cdrom’: then also – this article describes how to go back from ... Read More
20x performance difference between two VMs running the same version of Elastic opendistro
i’ve just spent way too much time trying to figure out why the same query run on one VM with elastic 0.1s while on another – 2s. both VMs were running on the same physical server, had the same amount of cores allocated. i’ve finally found it – there was a tiny difference in amount ... Read More
ClickHouse – dictionary with string keys
i wanted to create a clickhouse dictionary that used String as a key, not an int. docs mention here: “A composite key can consist of a single element. This makes it possible to use a string as the key, for instance”. I’ve been trying this and failed few times. creation worked but i could not ... Read More
“initramfs unpacking failed: write error” due to stupid typo in virsh-install
i’ve been trying to set up a new vm using: trying and trying, and each time i got the same boot failure: root cause? allocating 128MB instead of intended 128GB of RAM for the VM. hopefully this post helps some poor soul who runs into a similar issue.
clickhouse – getting n most significant digits of a number
i’m testing some wild idea of finding matches in quite a large dataset. part of the problem is that scaling of input is unknown, 123 might be correct match for 1.23 or for 12.3. here’s an expression that returns me n=4 most significant digits of each float from the input array:
suddenly in-kernel communication between lxc containers gets erratic
we’re using LXC containers to host multiple workloads on the same physical servers. e.g. few instances of database servers running side-by-side. once in a while we end up with strange situation where tcp connections between containers running on the same physical server get torn down abruptly. in our case – this manifested e.g. by those ... Read More
apache2 – redirect from http to https with some source-ip-based exceptions
i was migrating a server from http to https. while header-based redirect worked for most of the clients, for some – i had to allow for a transition period where some configuration / code had to be adjusted. here’s the config that responds with 302 redir to most of the http requests, but for those ... Read More
switching source of SVN replica
i have svn replica that follows in near-real-time a master server using below run every few seconds: i had to change url of the source server; to reconfigure the the replica i’ve done:
changing source url of the svn repository replica
i have bunch of svn read-only replicas. they were created using: replication [ fetching of earlier not downloaded revisions ] is done via: to check from which url my replica repo fetches updates: to change it – run: that’s it – next execution of svnsync will fetch the data from the new origin url based ... Read More
fiddler returning “HTTP/1.1 502 Fiddler – Connection Failed” for HTTPs requests replied / made with it?
i’ve been using fiddler tool for ages. recently i’ve noticed most of my attempts of sending new requests fail with: solution? tools > options > [x] capture HTTPS CONNECTs > [x] Decrypt HTTPS traffic > protocols: enter there tls1.2 once it’s set you can un-tick [x] capture.
“Verify your Kindle document” for pdfs self-mailed to my kindle
whenever i travel i like to use kindle for reading some articles that i’ve earlier collected. for collecting i use a simple PHP script with rich text editor that allows me to copy & paste content and then mail it to my kindle address. recently i’ve started getting requests from Amazon to approve each document ... Read More
xiaomi robot vaccuum disassembly
i have 1st gen xiaomi mi robot vacuum cleaner. it’s been serving very well for the past 3 years. this video was very helpful with disassembly when i had to replace the main sucking motor fan: https://www.youtube.com/watch?v=wdDSBgJ1kRM i had to replace a fan and bought https://www.aliexpress.com/item/4000804127893.html instead of https://www.aliexpress.com/item/4000259186760.html ; not an exact fit but ... Read More
clickhouse
clickhouse is a column oriented OLAP database. i’ve started using it about half a year ago. i’m impressed. earlier i’ve read about it on percona’s blog but did not fully grasp how performant it was. i’ve tried it when i wrestling with MariaDB’s query planner on table with ~100M rows got me tired and each ... Read More
supermicro server getting stuck on “loading initial ramdisk”
i had a quite puzzling moment today when a server refused to boot up after routine maintenance. order of events: datacenter technician has taken server down and added Mellanox 25Gbit network card server booted up cleanly with Debian Buster and aged kernel 4.19.0-6 i’ve rebooted the server again and changed cpu performance settings in bios ... Read More