Azure Monitor Query client library for .NET - version 1.5.0

The Azure Monitor Query client library is used to execute read-only queries against Azure Monitor's two data platforms:

• Logs - Collects and organizes log and performance data from monitored resources. Data from different sources such as platform logs from Azure services, log and performance data from virtual machines agents, and usage and performance data from apps can be consolidated into a single Azure Log Analytics workspace. The various data types can be analyzed together using the Kusto Query Language.
• Metrics - Collects numeric data from monitored resources into a time series database. Metrics are numerical values that are collected at regular intervals and describe some aspect of a system at a particular time. Metrics are lightweight and capable of supporting near real-time scenarios, making them useful for alerting and fast detection of issues.

Resources:

• Source code
• NuGet package
• API reference documentation
• Service documentation
• Change log
• Migration guide from Application Insights
• Migration guide from Operational Insights

Getting started

Prerequisites

• An Azure subscription
• A TokenCredential implementation, such as an Azure Identity library credential type.
• To query Logs, you need one of the following things:
  • An Azure Log Analytics workspace
  • An Azure resource of any kind (Storage Account, Key Vault, Cosmos DB, etc.)
• To query Metrics, you need an Azure resource of any kind (Storage Account, Key Vault, Cosmos DB, etc.).

Install the package

Install the Azure Monitor Query client library for .NET with NuGet:

dotnet add package Azure.Monitor.Query

Authenticate the client

An authenticated client is required to query Logs or Metrics. To authenticate, create an instance of a TokenCredential class. Pass it to the constructor of the LogsQueryClient, MetricsClient, or MetricsQueryClient class. To satisfy the TokenCredential requirement, the following examples use DefaultAzureCredential from the Azure.Identity package.

Client for Logs queries

var client = new LogsQueryClient(new DefaultAzureCredential());

Clients for Metrics queries

For Metrics queries on a single Azure resource, use the following client:

var client = new MetricsQueryClient(new DefaultAzureCredential());

For Metrics queries across multiple Azure resources, use the following client:

var client = new MetricsClient(
    new Uri("https://<region>.metrics.monitor.azure.com"),
    new DefaultAzureCredential());

Configure client for Azure sovereign cloud

By default, LogsQueryClient, MetricsQueryClient, and MetricsClient are configured to use the Azure Public Cloud. To use a sovereign cloud instead, set the Audience property on the appropriate Options-suffixed class. For example:

// MetricsClient
var metricsClientOptions = new MetricsClientOptions
{
    Audience = MetricsClientAudience.AzureGovernment
};
var metricsClient = new MetricsClient(
    new Uri("https://usgovvirginia.metrics.monitor.azure.us"),
    new DefaultAzureCredential(),
    metricsClientOptions);

// MetricsQueryClient
var metricsQueryClientOptions = new MetricsQueryClientOptions
{
    Audience = MetricsQueryAudience.AzureGovernment
};
var metricsQueryClient = new MetricsQueryClient(
    new DefaultAzureCredential(),
    metricsQueryClientOptions);

// LogsQueryClient - by default, Azure Public Cloud is used
var logsQueryClient = new LogsQueryClient(
    new DefaultAzureCredential());

// LogsQueryClient With Audience Set
var logsQueryClientOptions = new LogsQueryClientOptions
{
    Audience = LogsQueryAudience.AzureChina
};
var logsQueryClientChina = new LogsQueryClient(
    new DefaultAzureCredential(),
    logsQueryClientOptions);

Execute the query

For examples of Logs and Metrics queries, see the Examples section.

Key concepts

Logs query rate limits and throttling

The Log Analytics service applies throttling when the request rate is too high. Limits, such as the maximum number of rows returned, are also applied on the Kusto queries. For more information, see Query API.

Metrics data structure

Each set of metric values is a time series with the following characteristics:

• The time the value was collected
• The resource associated with the value
• A namespace that acts like a category for the metric
• A metric name
• The value itself
• Some metrics have multiple dimensions as described in multi-dimensional metrics. Custom metrics can have up to 10 dimensions.

Thread safety

All client instance methods are thread-safe and independent of each other (guideline). This design ensures that the recommendation of reusing client instances is always safe, even across threads.

Additional concepts

Client options | Accessing the response | Long-running operations | Handling failures | Diagnostics | Mocking | Client lifetime

Examples

• Logs query
  • Workspace-centric logs query
  • Resource-centric logs query
  • Handle logs query response
  • Map logs query results to a model
  • Map logs query results to a primitive
  • Print logs query results as a table
• Batch logs query
• Advanced logs query scenarios
  • Set logs query timeout
  • Query multiple workspaces
  • Include statistics
  • Include visualization
• Metrics query
  • Handle metrics query response
  • Query metrics with options
  • Get metrics namespaces
  • Split a metric by dimension
  • Query metrics for multiple resources
• Register the client with dependency injection

Logs query

You can query logs by Log Analytics workspace ID or Azure resource ID. The result is returned as a table with a collection of rows.

Workspace-centric logs query

To query by workspace ID, use the LogsQueryClient.QueryWorkspaceAsync method:

string workspaceId = "<workspace_id>";
var client = new LogsQueryClient(new DefaultAzureCredential());

Response<LogsQueryResult> result = await client.QueryWorkspaceAsync(
    workspaceId,
    "AzureActivity | top 10 by TimeGenerated",
    new QueryTimeRange(TimeSpan.FromDays(1)));

LogsTable table = result.Value.Table;

foreach (var row in table.Rows)
{
    Console.WriteLine($"{row["OperationName"]} {row["ResourceGroup"]}");
}

Resource-centric logs query

To query by resource ID, use the LogsQueryClient.QueryResourceAsync method.

To find the resource ID:

1. Navigate to your resource's page in the Azure portal.
2. From the Overview blade, select the JSON View link.
3. In the resulting JSON, copy the value of the id property.

var client = new LogsQueryClient(new DefaultAzureCredential());

string resourceId = "/subscriptions/<subscription_id>/resourceGroups/<resource_group_name>/providers/<resource_provider>/<resource>";
string tableName = "<table_name>";
Response<LogsQueryResult> results = await client.QueryResourceAsync(
    new ResourceIdentifier(resourceId),
    $"{tableName} | distinct * | project TimeGenerated",
    new QueryTimeRange(TimeSpan.FromDays(7)));

LogsTable resultTable = results.Value.Table;
foreach (LogsTableRow row in resultTable.Rows)
{
    Console.WriteLine($"{row["OperationName"]} {row["ResourceGroup"]}");
}

foreach (LogsTableColumn columns in resultTable.Columns)
{
    Console.WriteLine("Name: " + columns.Name + " Type: " + columns.Type);
}

Handle logs query response

The QueryWorkspace method returns the LogsQueryResult, while the QueryBatch method returns the LogsBatchQueryResult. Here's a hierarchy of the response:

LogsQueryResult
|---Error
|---Status
|---Table
    |---Name
    |---Columns (list of `LogsTableColumn` objects)
        |---Name
        |---Type
    |---Rows (list of `LogsTableRows` objects)
        |---Count
|---AllTables (list of `LogsTable` objects)

Map logs query results to a model

You can map logs query results to a model using the LogsQueryClient.QueryWorkspaceAsync<T> method:

public class MyLogEntryModel
{
    public string ResourceGroup { get; set; }
    public int Count { get; set; }
}

var client = new LogsQueryClient(new DefaultAzureCredential());
string workspaceId = "<workspace_id>";

// Query TOP 10 resource groups by event count
Response<IReadOnlyList<MyLogEntryModel>> response = await client.QueryWorkspaceAsync<MyLogEntryModel>(
    workspaceId,
    "AzureActivity | summarize Count = count() by ResourceGroup | top 10 by Count",
    new QueryTimeRange(TimeSpan.FromDays(1)));

foreach (var logEntryModel in response.Value)
{
    Console.WriteLine($"{logEntryModel.ResourceGroup} had {logEntryModel.Count} events");
}

Map logs query results to a primitive

If your query returns a single column (or a single value) of a primitive type, use the LogsQueryClient.QueryWorkspaceAsync<T> overload to deserialize it:

string workspaceId = "<workspace_id>";

var client = new LogsQueryClient(new DefaultAzureCredential());

// Query TOP 10 resource groups by event count
Response<IReadOnlyList<string>> response = await client.QueryWorkspaceAsync<string>(
    workspaceId,
    "AzureActivity | summarize Count = count() by ResourceGroup | top 10 by Count | project ResourceGroup",
    new QueryTimeRange(TimeSpan.FromDays(1)));

foreach (var resourceGroup in response.Value)
{
    Console.WriteLine(resourceGroup);
}

Print logs query results as a table

You can also dynamically inspect the list of columns. The following example prints the query result as a table:

string workspaceId = "<workspace_id>";

var client = new LogsQueryClient(new DefaultAzureCredential());
Response<LogsQueryResult> response = await client.QueryWorkspaceAsync(
    workspaceId,
    "AzureActivity | top 10 by TimeGenerated",
    new QueryTimeRange(TimeSpan.FromDays(1)));

LogsTable table = response.Value.Table;

foreach (var column in table.Columns)
{
    Console.Write(column.Name + ";");
}

Console.WriteLine();

var columnCount = table.Columns.Count;
foreach (var row in table.Rows)
{
    for (int i = 0; i < columnCount; i++)
    {
        Console.Write(row[i] + ";");
    }

    Console.WriteLine();
}

Batch logs query

You can execute multiple logs queries in a single request using the LogsQueryClient.QueryBatchAsync method:

string workspaceId = "<workspace_id>";

var client = new LogsQueryClient(new DefaultAzureCredential());

// Query TOP 10 resource groups by event count
// And total event count
var batch = new LogsBatchQuery();

string countQueryId = batch.AddWorkspaceQuery(
    workspaceId,
    "AzureActivity | count",
    new QueryTimeRange(TimeSpan.FromDays(1)));
string topQueryId = batch.AddWorkspaceQuery(
    workspaceId,
    "AzureActivity | summarize Count = count() by ResourceGroup | top 10 by Count",
    new QueryTimeRange(TimeSpan.FromDays(1)));

Response<LogsBatchQueryResultCollection> response = await client.QueryBatchAsync(batch);

var count = response.Value.GetResult<int>(countQueryId).Single();
var topEntries = response.Value.GetResult<MyLogEntryModel>(topQueryId);

Console.WriteLine($"AzureActivity has total {count} events");
foreach (var logEntryModel in topEntries)
{
    Console.WriteLine($"{logEntryModel.ResourceGroup} had {logEntryModel.Count} events");
}

Advanced logs query scenarios

Set logs query timeout

Some logs queries take longer than 3 minutes to execute. The default server timeout is 3 minutes. You can increase the server timeout to a maximum of 10 minutes. In the following example, the LogsQueryOptions object's ServerTimeout property is used to set the server timeout to 10 minutes:

string workspaceId = "<workspace_id>";

var client = new LogsQueryClient(new DefaultAzureCredential());

// Query TOP 10 resource groups by event count
Response<IReadOnlyList<string>> response = await client.QueryWorkspaceAsync<string>(
    workspaceId,
    @"AzureActivity
        | summarize Count = count() by ResourceGroup
        | top 10 by Count
        | project ResourceGroup",
    new QueryTimeRange(TimeSpan.FromDays(1)),
    new LogsQueryOptions
    {
        ServerTimeout = TimeSpan.FromMinutes(10)
    });

foreach (var resourceGroup in response.Value)
{
    Console.WriteLine(resourceGroup);
}

Query multiple workspaces

To run the same logs query against multiple workspaces, use the LogsQueryOptions.AdditionalWorkspaces property:

string workspaceId = "<workspace_id>";
string additionalWorkspaceId = "<additional_workspace_id>";

var client = new LogsQueryClient(new DefaultAzureCredential());

// Query TOP 10 resource groups by event count
Response<IReadOnlyList<string>> response = await client.QueryWorkspaceAsync<string>(
    workspaceId,
    @"AzureActivity
        | summarize Count = count() by ResourceGroup
        | top 10 by Count
        | project ResourceGroup",
    new QueryTimeRange(TimeSpan.FromDays(1)),
    new LogsQueryOptions
    {
        AdditionalWorkspaces = { additionalWorkspaceId }
    });

foreach (var resourceGroup in response.Value)
{
    Console.WriteLine(resourceGroup);
}

Include statistics

To get logs query execution statistics, such as CPU and memory consumption:

1. Set the LogsQueryOptions.IncludeStatistics property to true.
2. Invoke the GetStatistics method on the LogsQueryResult object.

The following example prints the query execution time:

string workspaceId = "<workspace_id>";
var client = new LogsQueryClient(new DefaultAzureCredential());

Response<LogsQueryResult> response = await client.QueryWorkspaceAsync(
    workspaceId,
    "AzureActivity | top 10 by TimeGenerated",
    new QueryTimeRange(TimeSpan.FromDays(1)),
    new LogsQueryOptions
    {
        IncludeStatistics = true,
    });

BinaryData stats = response.Value.GetStatistics();
using var statsDoc = JsonDocument.Parse(stats);
var queryStats = statsDoc.RootElement.GetProperty("query");
Console.WriteLine(queryStats.GetProperty("executionTime").GetDouble());

Because the structure of the statistics payload varies by query, a BinaryData return type is used. It contains the raw JSON response. The statistics are found within the query property of the JSON. For example:

{
  "query": {
    "executionTime": 0.0156478,
    "resourceUsage": {...},
    "inputDatasetStatistics": {...},
    "datasetStatistics": [{...}]
  }
}

Include visualization

To get visualization data for logs queries using the render operator:

1. Set the LogsQueryOptions.IncludeVisualization property to true.
2. Invoke the GetVisualization method on the LogsQueryResult object.

For example:

string workspaceId = "<workspace_id>";
var client = new LogsQueryClient(new DefaultAzureCredential());

Response<LogsQueryResult> response = await client.QueryWorkspaceAsync(
    workspaceId,
    @"StormEvents
        | summarize event_count = count() by State
        | where event_count > 10
        | project State, event_count
        | render columnchart",
    new QueryTimeRange(TimeSpan.FromDays(1)),
    new LogsQueryOptions
    {
        IncludeVisualization = true,
    });

BinaryData viz = response.Value.GetVisualization();
using var vizDoc = JsonDocument.Parse(viz);
var queryViz = vizDoc.RootElement.GetProperty("visualization");
Console.WriteLine(queryViz.GetString());

Because the structure of the visualization payload varies by query, a BinaryData return type is used. It contains the raw JSON response. For example:

{
  "visualization": "columnchart",
  "title": null,
  "accumulate": false,
  "isQuerySorted": false,
  "kind": null,
  "legend": null,
  "series": null,
  "yMin": "",
  "yMax": "",
  "xAxis": null,
  "xColumn": null,
  "xTitle": null,
  "yAxis": null,
  "yColumns": null,
  "ySplit": null,
  "yTitle": null,
  "anomalyColumns": null
}

Metrics query

You can query metrics on a single Azure resource using the MetricsQueryClient.QueryResourceAsync method. For each requested metric, a set of aggregated values is returned inside the TimeSeries collection.

A resource ID is required to query metrics. To find the resource ID:

1. Navigate to your resource's page in the Azure portal.
2. From the Overview blade, select the JSON View link.
3. In the resulting JSON, copy the value of the id property.

string resourceId =
    "/subscriptions/<subscription_id>/resourceGroups/<resource_group_name>/providers/<resource_provider>/<resource>";
var client = new MetricsQueryClient(new DefaultAzureCredential());

Response<MetricsQueryResult> results = await client.QueryResourceAsync(
    resourceId,
    new[] { "Average_% Free Space", "Average_% Used Space" }
);

foreach (MetricResult metric in results.Value.Metrics)
{
    Console.WriteLine(metric.Name);
    foreach (MetricTimeSeriesElement element in metric.TimeSeries)
    {
        Console.WriteLine("Dimensions: " + string.Join(",", element.Metadata));

        foreach (MetricValue value in element.Values)
        {
            Console.WriteLine(value);
        }
    }
}

Handle metrics query response

The metrics query API returns a MetricsQueryResult object. The MetricsQueryResult object contains properties such as a list of MetricResult-typed objects, Cost, Namespace, ResourceRegion, TimeSpan, and Interval. The MetricResult objects list can be accessed using the metrics param. Each MetricResult object in this list contains a list of MetricTimeSeriesElement objects. Each MetricTimeSeriesElement object contains Metadata and Values properties.

Here's a hierarchy of the response:

MetricsQueryResult
|---Cost
|---Granularity
|---Namespace
|---ResourceRegion
|---TimeSpan
|---Metrics (list of `MetricResult` objects)
    |---Id
    |---ResourceType
    |---Name
    |---Description
    |---Error
    |---Unit
    |---TimeSeries (list of `MetricTimeSeriesElement` objects)
        |---Metadata
        |---Values

Query metrics with options

A MetricsQueryOptions object can be used to support more granular metrics queries. Consider the following example, which queries an Azure Key Vault resource named TestVault. The resource's "Vault requests availability" metric is requested, as indicated by metric ID "Availability". Additionally, the "Avg" aggregation type is included.

string resourceId =
    "/subscriptions/<subscription_id>/resourceGroups/<resource_group_name>/providers/Microsoft.KeyVault/vaults/TestVault";
string[] metricNames = new[] { "Availability" };
var client = new MetricsQueryClient(new DefaultAzureCredential());
Response <MetricsQueryResult> result = await client.QueryResourceAsync(
    resourceId,
    metricNames,
    new MetricsQueryOptions
    {
        Aggregations =
        {
            MetricAggregationType.Average,
        }
    });

MetricResult metric = result.Value.Metrics[0];

foreach (MetricTimeSeriesElement element in metric.TimeSeries)
{
    foreach (MetricValue value in element.Values)
    {
        // Prints a line that looks like the following:
        // 6/21/2022 12:29:00 AM +00:00 : 100
        Console.WriteLine($"{value.TimeStamp} : {value.Average}");
    }
}

Get metrics namespaces

To programmatically retrieve metrics namespaces for an Azure resource, use the following code:

string resourceId =
    "/subscriptions/<subscription_id>/resourceGroups/<resource_group_name>/providers/Microsoft.Web/sites/TestWebApp";
var client = new MetricsQueryClient(new DefaultAzureCredential());

AsyncPageable<MetricNamespace> metricNamespaces = client.GetMetricNamespacesAsync(resourceId);

await foreach (var metricNamespace in metricNamespaces)
{
    Console.WriteLine($"Metric namespace = {metricNamespace.Name}");
}

Split a metric by dimension

The MetricsQueryOptions.Filter property can be used for splitting a metric by a dimension when its filter value is set to an asterisk. Consider the following example for an App Service resource named TestWebApp. The code queries the resource's Http2xx metric and splits it by the Instance dimension.

string resourceId =
    "/subscriptions/<subscription_id>/resourceGroups/<resource_group_name>/providers/Microsoft.Web/sites/TestWebApp";
string[] metricNames = new[] { "Http2xx" };
// Use of asterisk in filter value enables splitting on Instance dimension.
string filter = "Instance eq '*'";
var client = new MetricsQueryClient(new DefaultAzureCredential());

var options = new MetricsQueryOptions
{
    Aggregations =
    {
        MetricAggregationType.Average,
    },
    Filter = filter,
    TimeRange = TimeSpan.FromDays(2),
};
Response<MetricsQueryResult> result = await client.QueryResourceAsync(
    resourceId,
    metricNames,
    options);

foreach (MetricResult metric in result.Value.Metrics)
{
    foreach (MetricTimeSeriesElement element in metric.TimeSeries)
    {
        foreach (MetricValue value in element.Values)
        {
            // Prints a line that looks like the following:
            // Thursday, May 4, 2023 9:42:00 PM, webwk000002, Http2xx, 1
            Console.WriteLine(
                $"{value.TimeStamp:F}, {element.Metadata["Instance"]}, {metric.Name}, {value.Average}");
        }
    }
}

Query metrics for multiple resources

To query metrics for multiple Azure resources in a single request, use the MetricsClient.QueryResources method. This method:

• Calls a different API than the MetricsQueryClient methods.
• Requires a regional endpoint when creating the client. For example, "https://westus3.metrics.monitor.azure.com".

Each Azure resource must reside in:

• The same region as the endpoint specified when creating the client.
• The same Azure subscription.

Furthermore:

• The user must be authorized to read monitoring data at the Azure subscription level. For example, the Monitoring Reader role on the subscription to be queried.
• The metric namespace containing the metrics to be queried must be provided. For a list of metric namespaces, see Supported metrics and log categories by resource type.

string resourceId =
    "/subscriptions/<id>/resourceGroups/<rg-name>/providers/<source>/storageAccounts/<resource-name-1>";
var client = new MetricsClient(
    new Uri("https://<region>.metrics.monitor.azure.com"),
    new DefaultAzureCredential());
Response<MetricsQueryResourcesResult> result = await client.QueryResourcesAsync(
    resourceIds: new List<ResourceIdentifier> { new ResourceIdentifier(resourceId) },
    metricNames: new List<string> { "Ingress" },
    metricNamespace: "Microsoft.Storage/storageAccounts").ConfigureAwait(false);

MetricsQueryResourcesResult metricsQueryResults = result.Value;
foreach (MetricsQueryResult value in metricsQueryResults.Values)
{
    Console.WriteLine(value.Metrics.Count);
}

For an inventory of metrics and dimensions available for each Azure resource type, see Supported metrics with Azure Monitor.

The QueryResources method also accepts a MetricsQueryResourcesOptions-typed argument, in which the user can specify extra properties to filter the results. The following example demonstrates the OrderBy and Size properties:

string resourceId =
    "/subscriptions/<id>/resourceGroups/<rg-name>/providers/<source>/storageAccounts/<resource-name-1>";
var client = new MetricsClient(
    new Uri("https://<region>.metrics.monitor.azure.com"),
    new DefaultAzureCredential());
var options = new MetricsQueryResourcesOptions
{
    OrderBy = "sum asc",
    Size = 10
};

Response<MetricsQueryResourcesResult> result = await client.QueryResourcesAsync(
    resourceIds: new List<ResourceIdentifier> { new ResourceIdentifier(resourceId) },
    metricNames: new List<string> { "Ingress" },
    metricNamespace: "Microsoft.Storage/storageAccounts",
    options).ConfigureAwait(false);

MetricsQueryResourcesResult metricsQueryResults = result.Value;
foreach (MetricsQueryResult value in metricsQueryResults.Values)
{
    Console.WriteLine(value.Metrics.Count);
}

Register the client with dependency injection

To register a client with the dependency injection container, invoke the corresponding extension method.

Client	Extension method
LogsQueryClient	AddLogsQueryClient
MetricsClient	AddMetricsClient
MetricsQueryClient	AddMetricsQueryClient

For more information, see Register client.

Troubleshooting

To diagnose various failure scenarios, see the troubleshooting guide.

Next steps

To learn more about Azure Monitor, see the Azure Monitor service documentation.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit cla.microsoft.com.

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately with labels and comments. Follow the instructions provided by the bot. You'll only need to sign the CLA once across all Microsoft repos.

This project has adopted the Microsoft Open Source Code of Conduct. For more information, see the Code of Conduct FAQ or contact opencode@microsoft.com with any questions or comments.