On 21/04/2019 19.26, Florian Gleixner wrote:
On 21.04.19 12:24, Carlos E. R. wrote:
If it uses Java it will probably be memory expensive?
No and yes. Java and memory is like projects and money. If you put more memory/money in Java/projects you will likely succeed, but you may fail too. If you look closer, sometimes another strategy will be better.
If you look at solr, then you will see, that solr uses 2 memory resources: java heap memory and unix filesystem cache.
Java heap memory is the internal java memory for variables and so on. You can set a minimum and a maximum with -Xms and -Xmx. Both are set by default to 512M for solr, and this is enough for most dovecot installations. If you get out of memory errors in the solr log, then set -Xmx higher. If the heap usage is always over 512M, then set -Xms higher. Easy.
Solr/lucene uses memory mapping for the search index. So it relies on the unix filesystem cache to keep hot data in memory. So solr is fast, if all of your frequently queried solr index data stay in the filesystem cache. Putting all your memory in the Java heap via -Xmx/-Xms slows down solr, because there is no memory left for the filesystem cache and index data have to be read from disk over and over again.
Considering that my system is tight on memory, I can not use this, unless memory is released immediately after the index is created. -- Cheers / Saludos, Carlos E. R. (from openSUSE, Leap 15.1 x86_64 (ssd-test)) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org