Example #1
0
        private static void ProcessCounterEmit(CounterEmit emit)
        {
            // This is an expensive call, so make sure that we only make it once
            string counterName = emit.GetCounterName();
            int    hashCode    = CounterInstance.GetCounterHashCode(emit.Name, emit.Dimensions);

            CounterInstance instance;

            if (!instanceByNameCache.TryGetValue(counterName, out instance))
            {
                // The counter is not in the cache, so we need to get/create is in the database
                using (var db = new CounterDatabase())
                {
                    if (!TryGetInstanceFromDatabase(emit, hashCode, db, out instance))
                    {
                        CounterInstanceData counterInstanceData =
                            new CounterInstanceData()
                        {
                            Name             = emit.Name,
                            InstanceHashCode = hashCode
                        };

                        if (counterInstanceData.Dimensions == null)
                        {
                            counterInstanceData.Dimensions = new List <CounterDimensionData>();
                        }

                        foreach (KeyValuePair <string, string> emitDimension in emit.Dimensions)
                        {
                            counterInstanceData.Dimensions.Add(
                                new CounterDimensionData(emitDimension.Key, emitDimension.Value));
                        }

                        db.Instances.Add(counterInstanceData);
                        db.SaveChanges();

                        instance = new CounterInstance(counterInstanceData);
                    }

                    // Add the newly created/retrieved counter instance to the cache
                    // TODO: Where does the TTL go???
                    instanceByNameCache.TryAdd(counterName, instance);
                }
            }

            long ts = Convert.ToInt64(Math.Floor(emit.Timestamp.Subtract(Epoch).TotalSeconds));

            CounterValueSet valueSet;

            // Check if there is a valueSet for this particular timestamp. If not, add one
            if (!instance.Values.TryGetValue(ts, out valueSet))
            {
                valueSet = new CounterValueSet(emit.Value, 1);
                instance.Values.Add(ts, valueSet);
                return;
            }

            valueSet.Sum += emit.Value;
            valueSet.Count++;
        }
Example #2
0
        private static void FlushCountersToDatabase()
        {
            DateTime now = DateTime.UtcNow;
            long     timestampThreadhold = Convert.ToInt64(Math.Floor(now.Subtract(Epoch).TotalSeconds)) - 2;

            using (var db = new CounterDatabase())
            {
                bool valuesAdded = false;
                foreach (string counterName in instanceByNameCache.Keys)
                {
                    CounterInstance instance = instanceByNameCache[counterName];

                    // Push any values older than the threshold into the db and remove from the cache
                    List <long> removeList = new List <long>();
                    foreach (long timestamp in instance.Values.Keys)
                    {
                        if (timestamp < timestampThreadhold)
                        {
                            CounterValueSet valueSet = instance.Values[timestamp];
                            db.Values.Add(
                                new CounterValueData()
                            {
                                Count             = valueSet.Count,
                                CounterInstanceId = instance.Id,
                                Flags             = (int)CounterValueFlags.Aggregate1Second,
                                Timestamp         = timestamp,
                                Value             = valueSet.Sum
                            });

                            // Remove the value set from the instance, since we already pushed it to the DB
                            removeList.Add(timestamp);
                            valuesAdded = true;
                        }
                    }

                    foreach (long timestamp in removeList)
                    {
                        instance.Values.Remove(timestamp);
                    }

                    if (instance.CacheExpiryDateTime < now && !instance.Values.Any())
                    {
                        instanceByNameCache.TryRemove(counterName, out CounterInstance _);
                    }
                }

                if (valuesAdded)
                {
                    db.SaveChanges();
                }
            }
        }
Example #3
0
        private static bool TryGetInstanceFromDatabase(
            CounterEmit emit,
            int emitHashCode,
            CounterDatabase db,
            out CounterInstance instance)
        {
            var instances = db.Instances
                            .Where(i => i.InstanceHashCode == emitHashCode)
                            .Include(i => i.Dimensions);

            foreach (CounterInstanceData counterInstance in instances)
            {
                if (emit.IsMatch(counterInstance))
                {
                    instance = new CounterInstance(counterInstance);
                    return(true);
                }
            }

            instance = null;
            return(false);
        }