feat: Add an option to disable the file system watcher. (#2536)

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

@@ -797,6 +797,8 @@ public partial class configurationService
 
  private bool forceNewTransactionOnNewThreadField;
 
+ private bool disableFileSystemWatcherField;
+
  /// <summary>
  /// configurationService class constructor
  /// </summary>
@@ -810,6 +812,7 @@ public configurationService()
  this.sendDataOnExitThresholdField = ((float)(60000F));
  this.completeTransactionsOnThreadField = false;
  this.forceNewTransactionOnNewThreadField = false;
+ this.disableFileSystemWatcherField = false;
  }
 
  public string obscuringKey
@@ -1032,6 +1035,20 @@ public bool forceNewTransactionOnNewThread
  }
  }
 
+ [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 configurationService object

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

@@ -223,6 +223,14 @@
  </xs:annotation>
  </xs:attribute>
 
+ <xs:attribute name="disableFileSystemWatcher" type="xs:boolean" default="false">
+ <xs:annotation>
+ <xs:documentation>
+ If disableFileSystemWatcher is set to true, then newrelic.config and 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/Config/ConfigurationTracker.cs

@@ -25,6 +25,12 @@ public class ConfigurationTracker : IDisposable
 
  public ConfigurationTracker(IConfigurationService configurationService, INativeMethods nativeMethods)
  {
+ if (configurationService.Configuration.DisableFileSystemWatcher)
+ {
+ Log.Debug("Live updates to newrelic.config will not be applied because they have been disabled by local configuration.");
+ return;
+ }
+
  _nativeMethods = nativeMethods;
  var fileName = configurationService.Configuration.NewRelicConfigFilePath;
  if (fileName == null)

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

@@ -2058,6 +2058,19 @@ public IEnumerable<IDictionary<string, string>> IgnoredInstrumentation
  }
  }
 
+ public bool DisableFileSystemWatcher
+ {
+ get
+ {
+ if(ServerlessModeEnabled || !LoggingEnabled)
+ {
+ return true;
+ }
+
+ return EnvironmentOverrides(_localConfiguration.service.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", "service" }, "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/Configuration/DefaultConfigurationTests.cs

@@ -4023,6 +4023,39 @@ public void LoggingLevelValueIsCached()
 
  #endregion Agent Logs
 
+ [TestCase(false, null, true, false, ExpectedResult = false)] // default
+ [TestCase(true, null, true, false, ExpectedResult = true)]
+ [TestCase(false, true, true, false, ExpectedResult = true)]
+ [TestCase(true, false, true, false, ExpectedResult = false)]
+ [TestCase(false, null, false, false, ExpectedResult = true)]
+ [TestCase(false, null, false, true, ExpectedResult = true)]
+ [TestCase(false, null, true, true, ExpectedResult = true)]
+ [TestCase(true, null, false, false, ExpectedResult = true)]
+ [TestCase(true, null, false, true, ExpectedResult = true)]
+ [TestCase(true, null, true, true, ExpectedResult = true)]
+ [TestCase(false, true, false, false, ExpectedResult = true)]
+ [TestCase(false, true, false, true, ExpectedResult = true)]
+ [TestCase(false, true, true, true, ExpectedResult = true)]
+ [TestCase(true, false, false, false, ExpectedResult = true)]
+ [TestCase(true, false, false, true, ExpectedResult = true)]
+ [TestCase(true, false, true, true, ExpectedResult = true)]
+ public bool ValidateDisableFileSystemWatcher(bool localWatcherDisabled, bool? envWatcherDisabled, bool loggingEnabled, bool serverlessMode)
+ {
+ // Setup config values
+ _localConfig.service.disableFileSystemWatcher = localWatcherDisabled;
+
+ if (envWatcherDisabled.HasValue)
+ {
+ Mock.Arrange(() => _environment.GetEnvironmentVariable("NEW_RELIC_DISABLE_FILE_SYSTEM_WATCHER")).Returns(envWatcherDisabled.ToString().ToLower());
+ }
+
+ _localConfig.log.enabled = loggingEnabled;
+ Mock.Arrange(() => _bootstrapConfiguration.ServerlessModeEnabled).Returns(serverlessMode);
+
+ // test
+ return _defaultConfig.DisableFileSystemWatcher;
+ }
+
  private void CreateDefaultConfiguration()
  {
  _defaultConfig = new TestableDefaultConfiguration(_environment, _localConfig, _serverConfig, _runTimeConfig, _securityPoliciesConfiguration, _bootstrapConfiguration, _processStatic, _httpRuntimeStatic, _configurationManagerStatic, _dnsStatic);