Hi,
I made it tunable. It should capture it from OS env BUFSIZE=8192, and java
property -DBUFSIZE=8192.
It logs actual value under INFO for FastWriter
https://github.com/mkhludnev/lucene-solr/commit/f0ed425bcbb16c50d01f3ff7fba3879148f50568
Here's a jar
https://github.com/mkhludnev/lucene-solr/releases/tag/8.11.2-SNAPSHOT,
which one can drop into the installation. You absolutely need to re/move
solr-solrj-8.11.2.jar from the release.
Happy experimenting!
On Sat, Feb 25, 2023 at 1:43 AM Fikavec F <fika...@yandex.ru> wrote:
> jetty.xml used in default solr configuration, file downloaded by http and
> nginx maybe faster because in /etc/nginx/sites-available/default - location
> / { aio threads; sendfile on; }
> I'm reproduce this in Ubuntu on virtual machines in home PC:
>
> # 0 set /etc/sysctl.conf settings from
> https://darksideclouds.wordpress.com/2016/10/10/tuning-10gb-nics-highway-to-hell/
> # and for network adapter ens160
> sudo ip link set ens160 txqueuelen 10000
> sudo ip link set ens160 mtu 9000
>
> # 1 create 16Gb ram disk
> sudo mkdir -p /mnt/solrramdisk
> sudo mount -t tmpfs -o size=16G tmpfs /mnt/solrramdisk
>
> # 2 download and start solr
> cd /mnt/solrramdisk
> wget -O solr-8.11.2.tgz
> https://www.apache.org/dyn/closer.lua/lucene/solr/8.11.2/solr-8.11.2.tgz?action=download
> tar xzf solr-8.11.2.tgz
> ./solr-8.11.2/bin/solr start
>
> # 3 create 10G test file
> head -c 10G /dev/urandom >
> /mnt/solrramdisk/solr-8.11.2/server/solr-webapp/webapp/sample.bin
>
> # on other host with same mtu and /etc/sysctl.conf settings
> # 4 download test file from Solr Jetty
> wget --report-speed=bits -O /dev/null
> http://192.168.220.135:8983/solr/sample.bin
> # Result - 2023-02-24 21:42:29 (4.83 Gb/s) - ‘/dev/null’ saved
> [10737418240]
>
> # 5 download test file from nginx (in nginx set root /mnt/solrramdisk;)
> wget --report-speed=bits -O /dev/null
> http://192.168.220.135/solr-8.11.2/server/solr-webapp/webapp/sample.bin
> # Result - 2023-02-24 21:34:40 (7.28 Gb/s) - ‘/dev/null’ saved
> [10737418240/10737418240]
>
> In virtual network with two virtual machines on the same host jetty faster
> (than 1.2 Gbit on my real hardware tests), but still slower Nginx and it
> doesn't explain why scrolling is significantly slower than Jetty's
> capabilities.
>
> Unfortunately, I am not a java developer and will not be able to offer
> a patch or rebuild the jar with a bigger buffer myself (without
> instructions on how to do it from scratch), but I can test/benchmark a new
> binary or any other Solr settings to find ways to speed up Solr Scroll.
> I'm hoping for a bigger buffer in FastWriter.java will speed up single
> thread data receiving, but this is a hypothesis that is better evaluated by
> specialists in the internal and network architecture of Solr. In my tests
> 1) Solr Jetty is able to give data much faster than they are given from
> collections. 2) Data from the collection is given at the same speed on
> servers that are quite different in performance (CPU cores are 30% slower,
> sas raid disk instead of ramdrive) with 10 Gbit network. 3) Multiple scroll
> does not increase the speed (disk and other Solr, OS caches do not help).
> Is there a mention somewhere that Solr, under any conditions, was able
> to send data from the collection faster than 400 Mbit in a single
> (single-threaded) connection? In which direction except FastWriter.java
> buffers can be searched for, what on modern fast hardware limits the data
> transfer rate during big collection scroll?
>
--
Sincerely yours
Mikhail Khludnev
https://t.me/MUST_SEARCH
A caveat: Cyrillic!
