matching: default to concurrency 1.2 number of CPUs

This tries to reduce PostgreSQL idling due to a) some matching being done from the Redis cache and b) latency between Node.js and PostgreSQL.

Author: derhuerst

lib/match.js

@@ -84,7 +84,7 @@ const runGtfsMatching = async (cfg, opt = {}) => {
 			//     COPY cpu_cores (num_cores) FROM PROGRAM 'sysctl -n hw.ncpu';
 			//     SELECT num_cores FROM cpu_cores LIMIT 1
 			// same as with hafas-gtfs-rt-feed: https://github.com/derhuerst/hafas-gtfs-rt-feed/blob/8.2.6/lib/match.js#L54-L61
-			: osCpus().length + 1,
+			: Math.ceil(1 + osCpus().length * 1.2),
 		publishUnmatchedTripUpdates: process.env.MATCHING_PUBLISH_UNMATCHED_TRIPUPDATES
 			? process.env.MATCHING_PUBLISH_UNMATCHED_TRIPUPDATES === 'true'
 			: false,