Merge pull request #5 from MindFlavor/pc_mapping/pr

Implemented performance counter filter

CommandLineOptions.cs

@@ -4,24 +4,35 @@
 public class CommandLineOptions
 {
     [JsonProperty(PropertyName = "instances")]
-    public List<SQLServerInstanceOptions> Instances { get; set; }
+    public List<SQLServerInstance> Instances { get; set; }
 
     [JsonProperty(PropertyName = "port")]
     public int Port { get; set; }
 
-    [JsonProperty(PropertyName = "waitStatsOptions")]
-    public WaitStatsOptions WaitStatsOptions { get; set; }
+    [JsonProperty(PropertyName = "waitStats")]
+    public WaitStats WaitStats { get; set; }
+
+    [JsonProperty(PropertyName = "performanceCounters")]
+    public PerformanceCounters PerformanceCounters { get; set; }
+}
+
+public class PerformanceCounters
+{
+    [JsonProperty(PropertyName = "templateFiles")]
+    public string[] TemplateFiles { get; set; }
+
+
 }
 
-public class SQLServerInstanceOptions
+public class SQLServerInstance
 {
     [JsonProperty(PropertyName = "connectionString")]
     public string ConnectionString { get; set; }
 }
 
-public class WaitStatsOptions
+public class WaitStats
 {
-    [JsonProperty(PropertyName = "waitStatsFiles")]
-    public string[] WaitStatsFiles { get; set; }
+    [JsonProperty(PropertyName = "templateFiles")]
+    public string[] TemplateFiles { get; set; }
 
 }

Counters/PerformanceCounters.cs

@@ -20,10 +20,16 @@ public struct GrafanaPerformanceCounter
     {
         public string type;
         public string name;
+
+        public override string ToString()
+        {
+            return $"{this.GetType().Name}[type == {type}, name == {name}]";
+        }
     }
 
     public class PerformanceCounters
     {
+        private static HashSet<string> EnabledCounters { get; set; }
         static Dictionary<string, GrafanaPerformanceCounter> _dGraf;
 
         public SQLServerInfo SQLServerInfo;
@@ -51,15 +57,44 @@ static PerformanceCounters()
             }
         }
 
-        private static string KeyFromObjectNameAndCounterName(string objectName, string counterName)
-        {
-            return objectName + "_" + counterName;
-        }
-
         public PerformanceCounters(HttpContext context, SQLServerInfo sqlServerInfo)
         {
             this.SQLServerInfo = sqlServerInfo;
             logger = context.RequestServices.GetRequiredService<ILogger<PerformanceCounters>>();
+
+            // in theory we should guard this code against concurrent access. It is possibile that
+            // two or more threads will work on the same HashSet concurrently because the all
+            // tested Waits == null to be true. In practice this will never happen as long as it's only
+            // one Prometheus calling our method. For now we will avoid the cost of a mutex, if bugs
+            // arise it will be included here.
+            if (EnabledCounters == null)
+            {
+                EnabledCounters = new HashSet<string>();
+
+                foreach (var file in Program.CommandLineOptions.PerformanceCounters.TemplateFiles)
+                {
+                    System.IO.FileInfo fi = new System.IO.FileInfo(file);
+                    logger.LogInformation($"Loading performance counter template to include from {fi.FullName}...");
+
+                    using (System.IO.StreamReader sr = new System.IO.StreamReader(new System.IO.FileStream(fi.FullName,
+                    System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read)))
+                    {
+                        string str;
+                        while ((str = sr.ReadLine()) != null)
+                        {
+                            if (str.StartsWith("#"))
+                                continue;
+
+                            EnabledCounters.Add(str);
+                        }
+                    }
+                }
+            }
+        }
+
+        private static string KeyFromObjectNameAndCounterName(string objectName, string counterName)
+        {
+            return objectName + "_" + counterName;
         }
 
         public async Task<string> QueryAndSerializeData()
@@ -98,6 +133,14 @@ public async Task<string> QueryAndSerializeData()
                             GrafanaPerformanceCounter gpc;
                             if (_dGraf.TryGetValue(key, out gpc))
                             {
+                                // skip this is it's not in the enabled performance counters
+                                // as specified by the template files configured.
+                                if (!EnabledCounters.Contains(gpc.name))
+                                {
+                                    logger.LogDebug($"PerformanceCounter {gpc} will be skipped because it's not in any configured template file");
+                                    continue;
+                                }
+
                                 string gpcName = $"sql_pc_{gpc.name}";
 
                                 sb.Append($"# TYPE {gpcName} {gpc.type}\n");

Counters/WaitStats.cs

@@ -38,10 +38,10 @@ public WaitStats(HttpContext context, SQLServerInfo sqlServerInfo)
             {
                 Waits = new HashSet<string>();
 
-                foreach (var file in Program.CommandLineOptions.WaitStatsOptions.WaitStatsFiles)
+                foreach (var file in Program.CommandLineOptions.WaitStats.TemplateFiles)
                 {
                     System.IO.FileInfo fi = new System.IO.FileInfo(file);
-                    logger.LogInformation($"Loading wait stats to include from {fi.FullName}...");
+                    logger.LogInformation($"Loading wait stats template to include from {fi.FullName}...");
 
                     using (System.IO.StreamReader sr = new System.IO.StreamReader(new System.IO.FileStream(fi.FullName,
                     System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read)))

MindFlavor.SQLServerExporter.csproj

@@ -3,6 +3,12 @@
   <PropertyGroup>
     <TargetFramework>netcoreapp2.2</TargetFramework>
     <AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>
+    <Version>0.2.0.0</Version>
+    <Authors>Francesco Cogno</Authors>
+    <Copyright>Apache License Version 2.0</Copyright>
+    <PackageLicenseUrl>https://raw.githubusercontent.com/MindFlavor/prometheus_sql_server_exporter/master/LICENSE</PackageLicenseUrl>
+    <PackageProjectUrl>https://mindflavor.github.io/prometheus_sql_server_exporter</PackageProjectUrl>
+    <RepositoryUrl>https://github.com/MindFlavor/prometheus_sql_server_exporter</RepositoryUrl>
   </PropertyGroup>
 
   <ItemGroup>

Program.cs

@@ -17,6 +17,10 @@ public class Program
         public static CommandLineOptions CommandLineOptions { get; private set; }
         public static void Main(string[] args)
         {
+            var assemblyVersion = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version;
+            System.Console.WriteLine($"Prometheus SQL Server Exporter v{assemblyVersion.ToString()}");
+            System.Console.WriteLine($"Licensed under Apache License 2.0\n");
+
             string configFile = null;
             for (int i = 0; (i < args.Length - 1 && configFile == null); i++)
                 if (args[i].ToLower() == "-c")