better error handling

diff --git a/plugins.d/sma_webbox.plugin b/plugins.d/sma_webbox.plugin
index 53007247fa3041b4ed54a777bc8afdab14bb6627..ac492c392e7de7e71b32a1d2c5a6cca46e1b830f 100755 (executable)
--- a/plugins.d/sma_webbox.plugin
+++ b/plugins.d/sma_webbox.plugin
@@ -144,6 +144,7 @@ function getSMAData(server, callback) {
        if(typeof(server.last_updated) === 'undefined')
                server.last_updated = 0;
 
+       // create an agent for keep-alive
        if(typeof(server.agent) === 'undefined') {
                server.agent = new http.Agent({
                        keepAlive: true,
@@ -153,18 +154,22 @@ function getSMAData(server, callback) {
                });
        }
 
+       // create the charts, if we haven't already
        if(typeof(server.created) === 'undefined') {
                netdata('CHART sma_webbox_' + server.name + '.current "" "Solar Power Production of ' + server.name + '" "Watts" sma_webbox_' + server.name + ' "" area 15000 ' + Math.round(UPDATE_EVERY / 1000));
                netdata('DIMENSION GriPwr power absolute 1 1');
+
                netdata('CHART sma_webbox_' + server.name + '.today "" "Today\'s Solar Power Production of ' + server.name + '" "kWatts" sma_webbox_' + server.name + ' "" area 15001 ' + Math.round(UPDATE_EVERY / 1000));
                netdata('DIMENSION GriEgyTdy today absolute 1 1000');
+
                netdata('CHART sma_webbox_' + server.name + '.total "" "Total Solar Power Production of ' + server.name + '" "kWatts" sma_webbox_' + server.name + ' "" area 15001 ' + Math.round(UPDATE_EVERY / 1000));
                netdata('DIMENSION GriEgyTot total absolute 1 1000');
+
                server.created = true;
        }
 
-       server.error = 500;
-       server.success = false;
+       // initialize our metrics to null
+       // so that we will know if we read them or not
        server.data = {
                'GriPwr': {
                        unit: null,
@@ -197,24 +202,38 @@ function getSMAData(server, callback) {
                agent: server.agent
        };
 
+       server.error = 0;
+       server.success = false;
        server.response = '';
        server.request = http.request(options, function(res) {
                res.setEncoding('utf8');
-               server.error = 0;
-
                server.response_code = res.statusCode;
 
                // check if we got HTTP/200
                if(server.response_code !== 200) {
-                       debug('Server responded with ' + server.response_code + ', failed to get data.');
-                       server.error = 503;
-                       server.running = false;
-                       server.success = false;
-                       if(typeof(callback) === 'function')
-                               callback(server);
+                       // if this request is in error and we have
+                       // handled it, don't do anything more
+                       if(server.error === 0) {
+                               debug('Server responded with ' + server.response_code + ', failed to get data.');
+                               server.error = 503;
+                               server.success = false;
+                               server.running = false;
+                               if(typeof(callback) === 'function')
+                                       callback(server);
+                       }
                }
 
+               res.on('data', function(chunk) {
+                       // read more data, only if there is no error
+                       if(server.error === 0)
+                               server.response += chunk;
+               });
+
                res.on('error', function() {
+                       // do we have already handled this error?
+                       if(server.error !== 0)
+                               return;
+
                        debug('Received HTTP read error, failed to get data.');
                        server.error = 504;
                        server.success = false;
@@ -223,11 +242,9 @@ function getSMAData(server, callback) {
                                callback(server);
                });
 
-               res.on('data', function(chunk) {
-                       server.response += chunk;
-               });
-
                res.on('end', function() {
+                       // if there is an error we have handled
+                       // don't do anything
                        if(server.error !== 0)
                                return;
 
@@ -250,8 +267,6 @@ function getSMAData(server, callback) {
                                                server.data[e.meta].unit = e.unit;
                                        }
                                }
-                               server.error = 0;
-                               server.last_updated = t;
 
                                if(server.data['GriPwr'].value !== null) {
                                        netdata('BEGIN sma_webbox_' + server.name + '.current ' + ((server.dt)?server.dt*1000:'').toString());
@@ -270,26 +285,37 @@ function getSMAData(server, callback) {
                                        netdata('SET GriEgyTot = ' + Math.round(server.data['GriEgyTot'].value * 1000));
                                        netdata('END');
                                }
+
+                               server.error = 0;
+                               server.success = true;
+                               server.last_updated = t;
                        }
                        catch(e) {
                                server.error = 501;
+                               server.success = false;
                                server.failure_message = e.message;
                                error('FAILED TO PARSE DATA: ' + e.message);
                        }
 
                        server.running = false;
-                       if(typeof(callback) === 'function') {
-                               server.success = true;
+                       if(typeof(callback) === 'function')
                                callback(server);
-                       }
                });
        });
 
        server.request.on('error', function(e) {
-               server.running = false;
+               // do we have already handled this error?
+               if(server.error !== 0)
+                       return;
+
                server.error = 502;
+               server.success = false;
+               server.running = false;
                server.failure_message = e.message;
                error('problem with request to ' + server.hostname + ': ' + e.message);
+
+               if(typeof(callback) === 'function')
+                       callback(server);
        });
 
        // write data to request body