increase child-process timeout and improve error handling

lib/workers/db-worker.js

@@ -568,7 +568,7 @@ process.on('message', function (data) {
 
     const cb = function (err, value) {
         process.send({
-            error: err,
+            error: Util.serializeError(err),
             txid: data.txid,
             pid: data.pid,
             value: value,
@@ -577,7 +577,7 @@ process.on('message', function (data) {
 
     if (!ready) {
         return void init(data.config, function (err) {
-            if (err) { return void cb(err); }
+            if (err) { return void cb(Util.serializeError(err)); }
             ready = true;
             cb();
         });

lib/workers/index.js

@@ -9,6 +9,7 @@ const PID = process.pid;
 
 const DB_PATH = 'lib/workers/db-worker';
 const MAX_JOBS = 16;
+const DEFAULT_QUERY_TIMEOUT = 60000 * 15; // increased from three to fifteen minutes because queries for very large files were taking as long as seven minutes
 
 Workers.initialize = function (Env, config, _cb) {
     var cb = Util.once(Util.mkAsync(_cb));
@@ -113,6 +114,7 @@ Workers.initialize = function (Env, config, _cb) {
         const txid = guid();
         var cb = Util.once(Util.mkAsync(Util.both(_cb, function (err /*, value */) {
             if (err !== 'TIMEOUT') { return; }
+            Log.debug("WORKER_TIMEOUT_CAUSE", msg);
             // in the event of a timeout the user will receive an error
             // but the state used to resend a query in the event of a worker crash
             // won't be cleared. This also leaks a slot that could be used to keep
@@ -132,7 +134,7 @@ Workers.initialize = function (Env, config, _cb) {
         state.tasks[txid] = msg;
 
         // default to timing out affter 180s if no explicit timeout is passed
-        var timeout = typeof(opt.timeout) !== 'undefined'? opt.timeout: 180000;
+        var timeout = typeof(opt.timeout) !== 'undefined'? opt.timeout: DEFAULT_QUERY_TIMEOUT;
         response.expect(txid, cb, timeout);
         state.worker.send(msg);
     };

www/common/common-util.js

@@ -30,6 +30,15 @@
         return JSON.parse(JSON.stringify(o));
     };
 
+    Util.serializeError = function (err) {
+        if (!(err instanceof Error)) { return err; }
+        var ser = {};
+        Object.getOwnPropertyNames(err).forEach(function (key) {
+            ser[key] = err[key];
+        });
+        return ser;
+    };
+
     Util.tryParse = function (s) {
         try { return JSON.parse(s); } catch (e) { return;}
     };
@@ -113,13 +122,13 @@
         var handle = function (id, args) {
             var fn = pending[id];
             if (typeof(fn) !== 'function') {
-                errorHandler("MISSING_CALLBACK", {
+                return void errorHandler("MISSING_CALLBACK", {
                     id: id,
                     args: args,
                 });
             }
             try {
-                pending[id].apply(null, Array.isArray(args)? args : [args]);
+                fn.apply(null, Array.isArray(args)? args : [args]);
             } catch (err) {
                 errorHandler('HANDLER_ERROR', {
                     error: err,