Hi all, I am using Solr 4.9 with Tomcat. Thanks to the suggestions from Yonik and Dmitry about the slow start up. Everything works fine now, but I noticed that the load average of the server is high because there is constantly heavy disk read access. Please point me some directions.
Some numbers about my system: RAM: 18G swap space: 2G number of documents: 27 million Solr home: 185G disk read access constantly 40-60M/s document cache size: 16K entries document cache hit ratio: 0.65 query cache size: 16K query cache hit ratio: 0.03 At first, I wondered if the disk read comes from swap, so I decreased the swappiness from 60 to 10, but the disk read is still there, which means that the disk read access does not result from swapping in. Then, I tried different document cache size and query different size. The effect on changing query cache size is not obvious. I tried 512, 16K, 256K entries and the hit ratio is between 0.01 to 0.03. For document cache, the larger cache size did improve the hit ratio of document cache size (I tried 512, 16K, 256K, 512K, 1024K and the hit ratio is between 0.58 - 0.87), but the disk read is still high. Is adjusting document cache size a reasonable direction? Or I should just increase the physical memory? Is there any method to estimate the right size of document cache (or other caches) and to estimate the size of physical memory needed? Thanks, Po-Yu
