increase timeout from one minute to three and decrease the number of parallel jobs per worker

lib/workers/index.js

@@ -8,7 +8,7 @@ const Workers = module.exports;
 const PID = process.pid;
 
 const DB_PATH = 'lib/workers/db-worker';
-const MAX_JOBS = 16;
+const MAX_JOBS = 8;
 
 Workers.initialize = function (Env, config, _cb) {
     var cb = Util.once(Util.mkAsync(_cb));
@@ -97,7 +97,7 @@ Workers.initialize = function (Env, config, _cb) {
         // track which worker is doing which jobs
         state.tasks[txid] = msg;
 
-        response.expect(txid, cb, 60000);
+        response.expect(txid, cb, 180000);
         state.worker.send(msg);
     };