--- title: Stackdriver overview: Adapter to deliver logs and metrics to Stackdriver location: https://istio.io/docs/reference/config/adapters/stackdriver.html layout: protoc-gen-docs number_of_entries: 10 ---

The `stackdriver` adapter enables Istio to deliver log and metric data to the Stackdriver logging and monitoring backend.

## Params

Configuration format for the `stackdriver` adapter.

Field | Type | Description
--- | --- | ---
`endpoint` | `string` | Endpoint URL to send stackdriver data - leave empty to use the StackDriver SDK’s default value (monitoring.googleapis.com).
`projectId` | `string` | GCP Project to attach metrics to.
`pushInterval` | `google.protobuf.Duration` | This adapter batches the data it sends to Stackdriver; we will push to stackdriver every push_interval. If no value is provided we default to once per minute.
`appCredentials` | `bool (oneof)` | Use Google’s Application Default Credentials to authorize calls made by the StackDriver SDK. See Google’s documentation.
`apiKey` | `string (oneof)` | The API Key to be used for auth.
`serviceAccountPath` | `string (oneof)` | The path to a Google service account credential file, relative to the Mixer. E.g. `/etc/opt/mixer/gcp-serviceaccount-creds.json` or `./testdata/my-test-account-creds.json`.
`metricInfo` | `map<string, Params.MetricInfo>` | A map of Istio metric name to Stackdriver metric info.
`logInfo` | `map<string, Params.LogInfo>` | A map of Istio LogEntry name to Stackdriver log info.

## Params.LogInfo

Describes how to represent an Istio Log in Stackdriver.

Field | Type | Description
--- | --- | ---
`labelNames` | `string[]` | The logging template provides a set of variables; these list the subset of variables that should be used to form Stackdriver labels for the log entry.
`payloadTemplate` | `string` | A golang text/template template that will be executed to construct the payload for this log entry. It will be given the full set of variables for the log to use to construct its result.
`httpMapping` | `Params.LogInfo.HttpRequestMapping` | If an HttpRequestMapping is provided, a HttpRequest object will be filled out for this log entry using the variables named in the mapping to populate the fields of the request struct from the instance’s variables.

## Params.LogInfo.HttpRequestMapping

Maps from template variable names to the various fields of Stackdriver’s HTTP request struct. See https://godoc.org/cloud.google.com/go/logging#HTTPRequest

Field | Type | Description
--- | --- | ---
`status` | `string` | template variable name to map into HTTPRequest.Status
`requestSize` | `string` | template variable name to map into HTTPRequest.RequestSize
`responseSize` | `string` | template variable name to map into HTTPRequest.ResponseSize
`latency` | `string` | template variable name to map into HTTPRequest.Latency
`localIp` | `string` | template variable name to map into HTTPRequest.LocalIP
`remoteIp` | `string` | template variable name to map into HTTPRequest.RemoteIP

## Params.MetricInfo

Describes how to represent an Istio metric in Stackdriver. See https://github.com/googleapis/googleapis/blob/master/google/api/metric.proto

Field | Type | Description
--- | --- | ---
`kind` | `google.api.MetricDescriptor.MetricKind` |
`value` | `google.api.MetricDescriptor.ValueType` |
`buckets` | `Params.MetricInfo.BucketsDefinition` | For metrics with a metric value of DISTRIBUTION, this provides a mechanism for configuring the buckets that will be used to store the aggregated values. This field must be provided for metrics declared to be of type DISTRIBUTION. This field will be ignored for non-distribution metric kinds.

## Params.MetricInfo.BucketsDefinition

Describes buckets for DISTRIBUTION valued metrics. TODO: look into using google.api.distribution.proto instead - we would pull it in but it has a ton of dependencies it doesn’t actually use.

Field | Type | Description
--- | --- | ---
`linearBuckets` | `Params.MetricInfo.BucketsDefinition.Linear (oneof)` | The linear buckets.
`exponentialBuckets` | `Params.MetricInfo.BucketsDefinition.Exponential (oneof)` | The exponential buckets.
`explicitBuckets` | `Params.MetricInfo.BucketsDefinition.Explicit (oneof)` | The explicit buckets.

## Params.MetricInfo.BucketsDefinition.Explicit

Specifies a set of buckets with arbitrary widths.

There are `size(bounds) + 1` (= `N`) buckets. Bucket `i` has the following boundaries:

- Upper bound (`0 <= i < N-1`): `bounds[i]`
- Lower bound (`1 <= i < N`): `bounds[i - 1]`

The `bounds` field must contain at least one element. If `bounds` has only one element, then there are no finite buckets, and that single element is the common boundary of the overflow and underflow buckets.

Field | Type | Description
--- | --- | ---
`bounds` | `double[]` | The values must be monotonically increasing.

## Params.MetricInfo.BucketsDefinition.Exponential

Specifies an exponential sequence of buckets that have a width that is proportional to the value of the lower bound. Each bucket represents a constant relative uncertainty on a specific value in the bucket.

There are `num_finite_buckets + 2` (= `N`) buckets. The two additional buckets are the underflow and overflow buckets.

Bucket `i` has the following boundaries:

- Upper bound (0 <= i < N-1): `scale * (growth_factor ^ i)`
- Lower bound (1 <= i < N): `scale * (growth_factor ^ (i - 1))`

Field | Type | Description
--- | --- | ---
`numFiniteBuckets` | `int32` | Must be greater than 0.
`growthFactor` | `double` | Must be greater than 1.
`scale` | `double` | Must be greater than 0.

## Params.MetricInfo.BucketsDefinition.Linear

Specifies a linear sequence of buckets that all have the same width (except overflow and underflow). Each bucket represents a constant absolute uncertainty on the specific value in the bucket.

There are `num_finite_buckets + 2` (= `N`) buckets. The two additional buckets are the underflow and overflow buckets.

Bucket `i` has the following boundaries:

- Upper bound (`0 <= i < N-1`): `offset + (width * i)`
- Lower bound (`1 <= i < N`): `offset + (width * (i - 1))`

Field | Type | Description
--- | --- | ---
`numFiniteBuckets` | `int32` | Must be greater than 0.
`width` | `double` | Must be greater than 0.
`offset` | `double` | Lower bound of the first bucket.

## google.api.MetricDescriptor.MetricKind

The kind of measurement. It describes how the data is reported.

Name | Description
--- | ---
`METRIC_KIND_UNSPECIFIED` | Do not use this default value.
`GAUGE` | An instantaneous measurement of a value.
`DELTA` | The change in a value during a time interval.
`CUMULATIVE` | A value accumulated over a time interval. Cumulative measurements in a time series should have the same start time and increasing end times, until an event resets the cumulative value to zero and sets a new start time for the following points.

## google.api.MetricDescriptor.ValueType

The value type of a metric.

Name | Description
--- | ---
`VALUE_TYPE_UNSPECIFIED` | Do not use this default value.
`BOOL` | The value is a boolean. This value type can be used only if the metric kind is `GAUGE`.
`INT64` | The value is a signed 64-bit integer.
`DOUBLE` | The value is a double precision floating point number.
`STRING` | The value is a text string. This value type can be used only if the metric kind is `GAUGE`.
`DISTRIBUTION` | The value is a `Distribution`.
`MONEY` | The value is money.