Hello! Look at the javadocs for both. The granularity of System.currentTimeMillis() depend on the operating system, so it may happen that calls to that method that are 1 millisecond away from each other still return the same value. This is not the case with System.nanoTime() - http://docs.oracle.com/javase/7/docs/api/java/lang/System.html
-- Regards, Rafał Kuć Performance Monitoring * Log Analytics * Search Analytics Solr & Elasticsearch Support * http://sematext.com/ > Hi > I have just compare the difference between the version 4.6.0 and 4.7.1. > Notice that the time in the getConnection function is declared with the > System.nanoTime in 4.7.1 ,while System.currentTimeMillis(). > Curious about the resson for the change.the benefit of it .Is it > neccessory? > I have read the SOLR-5734 , > https://issues.apache.org/jira/browse/SOLR-5734 > Do some google about the difference of currentTimeMillis and nano,but > still can not figure out it. > 2014-04-26 2:24 GMT+08:00 Shawn Heisey <s...@elyograg.org>: >> On 4/25/2014 11:56 AM, Hutchins, Jonathan wrote: >> >>> I recently upgraded from 4.6.1 to 4.7.1 and have found that the DIH >>> process that we are using takes 4x as long to complete. The only odd >>> thing I notice is when I enable debug logging for the dataimporthandler >>> process, it appears that in the new version each sql query is resulting in >>> a new connection opened through jdbcdatasource (log: >>> http://pastebin.com/JKh4gpmu). Were there any changes that would affect >>> the speed of running a full import? >>> >> >> This is most likely the problem you are experiencing: >> >> https://issues.apache.org/jira/browse/SOLR-5954 >> >> The fix will be in the new 4.8 version. The release process for 4.8 is >> underway right now. A second release candidate was required yesterday. If >> no further problems are encountered, the release should be made around the >> middle of next week. If problems are encountered, the release will be >> delayed. >> >> Here's something very important that has been mentioned before: Solr 4.8 >> will require Java 7. Previously, Java 6 was required. Java 7u55 (the >> current release from Oracle as I write this) is recommended as a minimum. >> >> If a 4.7.3 version is built, this is a fix that we should backport. >> >> Thanks, >> Shawn >> >>
