feat: Add an option to disable the instrumentation file system watcher.

src/Agent/NewRelic/Agent/Core/Config/Configuration.cs

@@ -1539,6 +1539,8 @@ public partial class configurationInstrumentation
 
  private bool logField;
 
+ private bool disableFileSystemWatcherField;
+
  /// <summary>
  /// configurationInstrumentation class constructor
  /// </summary>
@@ -1547,6 +1549,7 @@ public configurationInstrumentation()
  this.applicationsField = new List<configurationInstrumentationApplication>();
  this.rulesField = new List<configurationInstrumentationIgnore>();
  this.logField = false;
+ this.disableFileSystemWatcherField = false;
  }
 
  [System.Xml.Serialization.XmlArrayItemAttribute("ignore", IsNullable=false)]
@@ -1589,6 +1592,20 @@ public bool log
  }
  }
 
+ [System.Xml.Serialization.XmlAttributeAttribute()]
+ [System.ComponentModel.DefaultValueAttribute(false)]
+ public bool disableFileSystemWatcher
+ {
+ get
+ {
+ return this.disableFileSystemWatcherField;
+ }
+ set
+ {
+ this.disableFileSystemWatcherField = value;
+ }
+ }
+
  #region Clone method
  /// <summary>
  /// Create a clone of this configurationInstrumentation object

src/Agent/NewRelic/Agent/Core/Config/Configuration.xsd

@@ -487,6 +487,14 @@
  </xs:annotation>
  </xs:attribute>
 
+ <xs:attribute name="disableFileSystemWatcher" type="xs:boolean" default="false">
+ <xs:annotation>
+ <xs:documentation>
+ If disableFileSystemWatcher is set to true, then instrumentation XML file changes, additions, or deletions will not be detected and applied after the application has been started.
+ </xs:documentation>
+ </xs:annotation>
+ </xs:attribute>
+
  </xs:complexType>
  </xs:element>
 

src/Agent/NewRelic/Agent/Core/Configuration/DefaultConfiguration.cs

@@ -2058,6 +2058,14 @@ public IEnumerable<IDictionary<string, string>> IgnoredInstrumentation
  }
  }
 
+ public bool DisableFileSystemWatcher
+ {
+ get
+ {
+ return EnvironmentOverrides(_localConfiguration.instrumentation.disableFileSystemWatcher, "NEW_RELIC_DISABLE_FILE_SYSTEM_WATCHER");
+ }
+ }
+
  #region AI Monitoring
 
  public bool AiMonitoringEnabled

src/Agent/NewRelic/Agent/Core/Configuration/ReportedConfiguration.cs

@@ -662,6 +662,9 @@ public ReportedConfiguration(IConfiguration configuration)
  [JsonProperty("agent.instrumentation.ignore")]
  public IEnumerable<IDictionary<string, string>> IgnoredInstrumentation => _configuration.IgnoredInstrumentation;
 
+ [JsonProperty("agent.disable_file_system_watcher")]
+ public bool DisableFileSystemWatcher => _configuration.DisableFileSystemWatcher;
+
  [JsonProperty("agent.ai_monitoring.enabled")]
  public bool AiMonitoringEnabled => _configuration.AiMonitoringEnabled;
 

src/Agent/NewRelic/Agent/Core/Instrumentation/InstrumentationWatcher.cs

@@ -1,6 +1,7 @@
 // Copyright 2020 New Relic, Inc. All rights reserved.
 // SPDX-License-Identifier: Apache-2.0
 
+using NewRelic.Agent.Configuration;
 using NewRelic.Agent.Core.Utilities;
 using NewRelic.Agent.Core.Wrapper;
 using NewRelic.Core.Logging;
@@ -16,18 +17,26 @@ public class InstrumentationWatcher : IDisposable
 
  private readonly IInstrumentationService _instrumentationService;
  private readonly IWrapperService _wrapperService;
+ private readonly IConfigurationService _configurationService;
 
  private List<FileSystemWatcher> _fileWatchers;
  private SignalableAction _action;
 
- public InstrumentationWatcher(IWrapperService wrapperService, IInstrumentationService instrumentationService)
+ public InstrumentationWatcher(IWrapperService wrapperService, IInstrumentationService instrumentationService, IConfigurationService configurationService)
  {
  _wrapperService = wrapperService;
  _instrumentationService = instrumentationService;
+ _configurationService = configurationService;
  }
 
  public void Start()
  {
+ if (_configurationService.Configuration.DisableFileSystemWatcher)
+ {
+ Log.Debug("Live instrumentation updates due to instrumentation file changes will not be applied because they have been disabled by local configuration.");
+ return;
+ }
+
  if (AgentInstallConfiguration.HomeExtensionsDirectory == null)
  {
  Log.Warn("Live instrumentation updates due to instrumentation file changes will not be applied because HomeExtensionsDirectory is null.");

src/Agent/NewRelic/Agent/Extensions/NewRelic.Agent.Extensions/Configuration/IConfiguration.cs

@@ -212,7 +212,7 @@ public interface IConfiguration
  bool LoggingEnabled { get; }
  string LoggingLevel { get; }
  IEnumerable<IDictionary<string, string>> IgnoredInstrumentation { get; }
-
+ bool DisableFileSystemWatcher { get; }
  bool AiMonitoringEnabled { get; }
  bool AiMonitoringStreamingEnabled { get; }
  bool AiMonitoringRecordContentEnabled { get; }

tests/Agent/IntegrationTests/IntegrationTestHelpers/NewRelicConfigModifier.cs

@@ -497,5 +497,11 @@ public void SetDebugStartupDelaySeconds(int delaySeconds)
  CommonUtils.ModifyOrCreateXmlAttributeInNewRelicConfig(_configFilePath, new[] { "configuration", },
  "debugStartupDelaySeconds", delaySeconds.ToString());
  }
+
+ public NewRelicConfigModifier SetDisableFileSystemWatcher(bool enabled = true)
+ {
+ CommonUtils.ModifyOrCreateXmlAttributeInNewRelicConfig(_configFilePath, new[] { "configuration", "instrumentation" }, "disableFileSystemWatcher", enabled.ToString().ToLower());
+ return this;
+ }
  }
 }

tests/Agent/IntegrationTests/IntegrationTests/ReJit/NetCore/RejitAddFile.cs

@@ -25,10 +25,12 @@ public abstract class RejitAddFileBase<TFixture> : NewRelicIntegrationTest<TFixt
  where TFixture:AspNetCoreReJitMvcApplicationFixture
  {
  private readonly AspNetCoreReJitMvcApplicationFixture _fixture;
+ private readonly bool _disableFileSystemWatcher;
 
- protected RejitAddFileBase(TFixture fixture, ITestOutputHelper output) : base(fixture)
+ protected RejitAddFileBase(TFixture fixture, ITestOutputHelper output, bool disableFileSystemWatcher) : base(fixture)
  {
  _fixture = fixture;
+ _disableFileSystemWatcher = disableFileSystemWatcher;
 
  _fixture.TestLogger = output;
  _fixture.Actions(
@@ -37,6 +39,7 @@ protected RejitAddFileBase(TFixture fixture, ITestOutputHelper output) : base(fi
  var configModifier = new NewRelicConfigModifier(_fixture.DestinationNewRelicConfigFilePath);
  configModifier.SetLogLevel("finest");
  configModifier.AutoInstrumentBrowserMonitoring(false);
+ configModifier.SetDisableFileSystemWatcher(disableFileSystemWatcher);
  },
  exerciseApplication: () =>
  {
@@ -61,20 +64,29 @@ public void Test()
  {
  //transactions
  new Assertions.ExpectedMetric { metricName = @"WebTransaction/MVC/Home/Index", callCount = 1 },
- new Assertions.ExpectedMetric { metricName = @"WebTransaction/Custom/MyCustomAddMetricName", callCount = 1 },
  new Assertions.ExpectedMetric { metricName = @"WebTransaction/MVC/Rejit/GetAddFile", callCount = 1 },
 
  // Unscoped
  new Assertions.ExpectedMetric { metricName = @"DotNet/HomeController/Index", callCount = 1 },
- new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", callCount = 1 },
- new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", callCount = 2 },
 
  // Scoped
  new Assertions.ExpectedMetric { metricName = @"DotNet/HomeController/Index", metricScope = "WebTransaction/MVC/Home/Index", callCount = 1 },
- new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", metricScope = "WebTransaction/Custom/MyCustomAddMetricName", callCount = 1 },
  new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", metricScope = "WebTransaction/MVC/Rejit/GetAddFile", callCount = 1 }
  };
 
+ // Id file system watcher is disabled, these won't exist.
+ if (_disableFileSystemWatcher)
+ {
+ expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", callCount = 1 });
+ }
+ else
+ {
+ expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"WebTransaction/Custom/MyCustomAddMetricName", callCount = 1 });
+ expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", callCount = 1 });
+ expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", metricScope = "WebTransaction/Custom/MyCustomAddMetricName", callCount = 1 });
+ expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", callCount = 2 });
+ }
+
  var metrics = CommonUtils.GetMetrics(_fixture.AgentLog);
  _fixture.TestLogger?.WriteLine(_fixture.AgentLog.GetFullLogAsString());
 
@@ -84,18 +96,26 @@ public void Test()
  }
  }
 
- public class RejitAddFile : RejitAddFileBase<AspNetCoreReJitMvcApplicationFixture>
+ public class RejitAddFileWithFileWatcherEnabled : RejitAddFileBase<AspNetCoreReJitMvcApplicationFixture>
+ {
+ public RejitAddFileWithFileWatcherEnabled(AspNetCoreReJitMvcApplicationFixture fixture, ITestOutputHelper output)
+ : base(fixture, output, false)
+ {
+ }
+ }
+
+ public class RejitAddFileWithFileWatcherDisabled : RejitAddFileBase<AspNetCoreReJitMvcApplicationFixture>
  {
- public RejitAddFile(AspNetCoreReJitMvcApplicationFixture fixture, ITestOutputHelper output)
- : base(fixture, output)
+ public RejitAddFileWithFileWatcherDisabled(AspNetCoreReJitMvcApplicationFixture fixture, ITestOutputHelper output)
+ : base(fixture, output, true)
  {
  }
  }
 
  public class RejitAddFileWithTieredCompilation : RejitAddFileBase<AspNetCoreReJitMvcApplicationFixtureWithTieredCompilation>
  {
  public RejitAddFileWithTieredCompilation(AspNetCoreReJitMvcApplicationFixtureWithTieredCompilation fixture, ITestOutputHelper output)
- : base(fixture, output)
+ : base(fixture, output, false)
  {
  }
  }

tests/Agent/IntegrationTests/IntegrationTests/ReJit/NetFramework/RejitAddFile.cs

@@ -20,21 +20,25 @@ namespace NewRelic.Agent.IntegrationTests.ReJit.NetFramework
  /// Files: Integration.Testing.AddXmlFileTest.xml
  /// </summary>
  [NetFrameworkTest]
- public class RejitAddFile : NewRelicIntegrationTest<AspNetFrameworkReJitMvcApplicationFixture>
+ public abstract class RejitAddFileBase<TFixture> : NewRelicIntegrationTest<TFixture>
+ where TFixture : AspNetFrameworkReJitMvcApplicationFixture
  {
  private readonly AspNetFrameworkReJitMvcApplicationFixture _fixture;
+ private readonly bool _disableFileSystemWatcher;
 
- public RejitAddFile(AspNetFrameworkReJitMvcApplicationFixture fixture, ITestOutputHelper output)
+ public RejitAddFileBase(TFixture fixture, ITestOutputHelper output, bool disableFileSystemWatcher)
  : base(fixture)
  {
  _fixture = fixture;
+ _disableFileSystemWatcher = disableFileSystemWatcher;
 
  _fixture.TestLogger = output;
  _fixture.Actions(
  setupConfiguration: () =>
  {
  var configModifier = new NewRelicConfigModifier(_fixture.DestinationNewRelicConfigFilePath);
  configModifier.AutoInstrumentBrowserMonitoring(false);
+ configModifier.SetDisableFileSystemWatcher(disableFileSystemWatcher);
  },
  exerciseApplication: () =>
  {
@@ -59,20 +63,29 @@ public void Test()
  {
  //transactions
  new Assertions.ExpectedMetric { metricName = @"WebTransaction/MVC/HomeController/Index", CallCountAllHarvests = 1 },
- new Assertions.ExpectedMetric { metricName = @"WebTransaction/Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 },
  new Assertions.ExpectedMetric { metricName = @"WebTransaction/MVC/RejitController/GetAddFile", CallCountAllHarvests = 1 },
 
  // Unscoped
  new Assertions.ExpectedMetric { metricName = @"DotNet/HomeController/Index", CallCountAllHarvests = 1 },
- new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 },
- new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", CallCountAllHarvests = 2 },
 
  // Scoped
  new Assertions.ExpectedMetric { metricName = @"DotNet/HomeController/Index", metricScope = "WebTransaction/MVC/HomeController/Index", CallCountAllHarvests = 1 },
- new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", metricScope = "WebTransaction/Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 },
  new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", metricScope = "WebTransaction/MVC/RejitController/GetAddFile", CallCountAllHarvests = 1 }
  };
 
+ // Id file system watcher is disabled, these won't exist.
+ if (_disableFileSystemWatcher)
+ {
+ expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", CallCountAllHarvests = 1 });
+ }
+ else
+ {
+ expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"WebTransaction/Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 });
+ expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 });
+ expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", metricScope = "WebTransaction/Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 });
+ expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", CallCountAllHarvests = 2 });
+ }
+
  var metrics = CommonUtils.GetMetrics(_fixture.AgentLog);
  _fixture.TestLogger?.WriteLine(_fixture.AgentLog.GetFullLogAsString());
 
@@ -81,4 +94,20 @@ public void Test()
  );
  }
  }
+
+ public class RejitAddFileWithFileWatcherEnabled : RejitAddFileBase<AspNetFrameworkReJitMvcApplicationFixture>
+ {
+ public RejitAddFileWithFileWatcherEnabled(AspNetFrameworkReJitMvcApplicationFixture fixture, ITestOutputHelper output)
+ : base(fixture, output, false)
+ {
+ }
+ }
+
+ public class RejitAddFileWithFileWatcherDisabled : RejitAddFileBase<AspNetFrameworkReJitMvcApplicationFixture>
+ {
+ public RejitAddFileWithFileWatcherDisabled(AspNetFrameworkReJitMvcApplicationFixture fixture, ITestOutputHelper output)
+ : base(fixture, output, true)
+ {
+ }
+ }
 }

tests/Agent/UnitTests/Core.UnitTest/DataTransport/ExhaustiveTestConfiguration.cs

@@ -440,6 +440,8 @@ public class ExhaustiveTestConfiguration : IConfiguration
  new Dictionary<string, string> { { "assemblyName", "AssemblyToIgnore2" }, { "className", "ClassNameToIgnore" } }
  };
 
+ public bool DisableFileSystemWatcher => false;
+
  public TimeSpan MetricsHarvestCycle => TimeSpan.FromMinutes(1);
 
  public TimeSpan TransactionTracesHarvestCycle => TimeSpan.FromMinutes(1);