Google Cloud Storage

Google Cloud Long-Term Storage

Synopsis

Creates a target that writes log messages to Google Cloud Storage buckets with support for various file formats, authentication methods, and multipart uploads. The target handles large file uploads efficiently with configurable rotation based on size or event count.

Schema

- name: <string>
  description: <string>
  type: gcs
  pipelines: <pipeline[]>
  status: <boolean>
  properties:
    key: <string>
    secret: <string>
    project_id: <string>
    region: <string>
    endpoint: <string>
    part_size: <numeric>
    bucket: <string>
    buckets:
      - bucket: <string>
        name: <string>
        format: <string>
        compression: <string>
        extension: <string>
        schema: <string>
    name: <string>
    format: <string>
    compression: <string>
    extension: <string>
    schema: <string>
    max_size: <numeric>
    batch_size: <numeric>
    timeout: <numeric>
    field_format: <string>
    interval: <string|numeric>
    cron: <string>
    debug:
      status: <boolean>
      dont_send_logs: <boolean>

Configuration

The following fields are used to define the target:

Field	Required	Default	Description
name	Y		Target name
description	N	-	Optional description
type	Y		Must be gcs
pipelines	N	-	Optional post-processor pipelines
status	N	true	Enable/disable the target

Google Cloud Storage Credentials

Field	Required	Default	Description
key	N*	-	Google Cloud Storage HMAC access key ID for authentication
secret	N*	-	Google Cloud Storage HMAC secret access key for authentication
project_id	Y	-	Google Cloud project ID
region	N	us-central1	Google Cloud region (e.g., us-central1, europe-west1, asia-east1)
endpoint	N	https://storage.googleapis.com	Custom GCS-compatible endpoint URL

* = Conditionally required. HMAC credentials (key and secret) are required unless using service account authentication with Application Default Credentials.

Connection

Field	Required	Default	Description
part_size	N	5	Multipart upload part size in megabytes (minimum 5MB)
timeout	N	30	Connection timeout in seconds
field_format	N	-	Data normalization format. See applicable Normalization section

Files

Field	Required	Default	Description
bucket	N*	-	Default GCS bucket name (acts as catch-all when buckets is also specified)
buckets	N*	-	Array of bucket configurations for file distribution
buckets.bucket	Y	-	GCS bucket name
buckets.name	Y	-	File name template
buckets.format	N	"json"	Output format: json, multijson, avro, parquet
buckets.compression	N	-	Compression algorithm. See Compression below
buckets.extension	N	Matches format	File extension override
buckets.schema	N**	-	Schema definition file path (required for Avro and Parquet formats)
name	N	"vmetric.{{.Timestamp}}.{{.Extension}}"	Default file name template (used with bucket for catch-all)
format	N	"json"	Default output format (used with bucket for catch-all)
compression	N	-	Default compression (used with bucket for catch-all)
extension	N	Matches format	Default file extension (used with bucket for catch-all)
schema	N	-	Default schema path (used with bucket for catch-all)
max_size	N	0	Maximum file size in bytes before rotation
batch_size	N	100000	Maximum number of messages per file

* = Either bucket or buckets must be specified.

** = Conditionally required for Avro and Parquet formats when using buckets.

note

When max_size is reached, the current file is uploaded to GCS and a new file is created. For unlimited file size, set the field to 0.

Scheduler

Field	Required	Default	Description
interval	N	realtime	Execution frequency. See Interval for details
cron	N	-	Cron expression for scheduled execution. See Cron for details

Debug Options

Field	Required	Default	Description
debug.status	N	false	Enable debug logging
debug.dont_send_logs	N	false	Process logs but don't send to target (testing)

Details

The Google Cloud Storage target provides enterprise-grade cloud storage integration with comprehensive file format support. GCS offers high durability (99.999999999%), strong consistency for read-after-write operations, and integration with Google Cloud's security and analytics ecosystem.

Authentication Methods

Supports HMAC credentials (access key and secret key) for S3-compatible API access. When deployed on Google Cloud infrastructure, can leverage service account authentication with Application Default Credentials without explicit credentials. HMAC keys can be created through the Google Cloud Console for programmatic access.

Storage Classes

Google Cloud Storage supports multiple storage classes for cost optimization:

Storage Class	Use Case
Standard	Frequently accessed data
Nearline	Data accessed less than once per month
Coldline	Data accessed less than once per quarter
Archive	Data accessed less than once per year

Available Regions

Google Cloud Storage is available in multiple regions worldwide:

Region Code	Location
us-central1	Iowa, USA
us-east1	South Carolina, USA
us-west1	Oregon, USA
europe-west1	Belgium
europe-west2	London, UK
europe-west3	Frankfurt, Germany
asia-east1	Taiwan
asia-northeast1	Tokyo, Japan
asia-southeast1	Singapore
australia-southeast1	Sydney, Australia

Bucket Routing

The target supports flexible bucket routing through pipeline configuration or explicit bucket settings:

Configuration-based routing: Define multiple buckets in the target configuration, each with its own format, compression, and schema settings. Logs are routed to specific buckets based on configuration.

Pipeline-based routing: Use the bucket field in pipeline processors to dynamically route logs to different buckets at runtime. This enables conditional routing based on log content, source, or other attributes.

Catch-all routing: When a log doesn't match any specific bucket configuration or when no bucket field is set in the pipeline, logs are routed to the catch-all bucket (configured via the bucket field in target properties).

Routing priority:

1. Pipeline bucket field (highest priority)
2. Configured buckets in buckets array (if bucket name matches)
3. Default bucket field (catch-all, lowest priority)

This multi-level routing enables flexible data distribution strategies, such as routing different log types to different buckets based on content analysis, source system, severity level, or any other runtime decision.

File Formats

Format	Description
json	Each log entry is written as a separate JSON line (JSONL format)
multijson	All log entries are written as a single JSON array
avro	Apache Avro format with schema
parquet	Apache Parquet columnar format with schema

Compression

Some formats support built-in compression to reduce storage costs and transfer times. When supported, compression is applied at the file/block level before upload.

Format	Default	Compression Codecs
JSON	-	Not supported
MultiJSON	-	Not supported
Avro	zstd	deflate, snappy, zstd
Parquet	zstd	gzip, snappy, zstd, brotli, lz4

File Management

Files are rotated based on size (max_size parameter) or event count (batch_size parameter), whichever limit is reached first. Template variables in file names enable dynamic file naming for time-based partitioning.

Templates

The following template variables can be used in file names:

Variable	Description	Example
{{.Year}}	Current year	2024
{{.Month}}	Current month	01
{{.Day}}	Current day	15
{{.Timestamp}}	Current timestamp in nanoseconds	1703688533123456789
{{.Format}}	File format	json
{{.Extension}}	File extension	json
{{.Compression}}	Compression type	zstd
{{.TargetName}}	Target name	my_logs
{{.TargetType}}	Target type	gcs
{{.Table}}	Bucket name	logs

Multipart Upload

Large files automatically use multipart upload protocol with configurable part size (part_size parameter). Default 5MB part size balances upload efficiency and memory usage.

Multiple Buckets

Single target can write to multiple GCS buckets with different configurations, enabling data distribution strategies (e.g., raw data to one bucket, processed data to another).

Schema Requirements

Avro and Parquet formats require schema definition files. Schema files must be accessible at the path specified in the schema parameter during target initialization.

Integration with Google Cloud

GCS integrates seamlessly with other Google Cloud services including BigQuery for analytics, Cloud Functions for serverless processing, and Cloud Logging for centralized logging.

Examples

Basic Configuration

The minimum configuration for a JSON GCS target:

targets:
  - name: basic_gcs
    type: gcs
    properties:
      key: "GOOG1EXAMPLE1234567890ABCDEFGHIJ"
      secret: "abcdefghijklmnopqrstuvwxyz1234567890ABCD"
      project_id: "my-project-123456"
      bucket: "datastream-logs"

Service Account Authentication

Configuration using Application Default Credentials:

targets:
  - name: gcs_service_account
    type: gcs
    properties:
      project_id: "my-project-123456"
      region: "us-central1"
      bucket: "datastream-logs"

Pipeline-Based Routing

Dynamic bucket routing using pipeline processors to analyze log content and route to appropriate buckets:

targets:
  - name: smart_routing_gcs
    type: gcs
    pipelines:
      - dynamic_routing
    properties:
      key: "GOOG1EXAMPLE1234567890ABCDEFGHIJ"
      secret: "abcdefghijklmnopqrstuvwxyz1234567890ABCD"
      project_id: "my-project-123456"
      region: "us-central1"
      buckets:
        - bucket: "security-events"
          name: "security-{{.Year}}-{{.Month}}-{{.Day}}.json"
          format: "json"
        - bucket: "application-events"
          name: "app-{{.Year}}-{{.Month}}-{{.Day}}.json"
          format: "json"
        - bucket: "system-events"
          name: "system-{{.Year}}-{{.Month}}-{{.Day}}.json"
          format: "json"
      bucket: "other-events"
      name: "other-{{.Timestamp}}.json"
      format: "json"

pipelines:
  - name: dynamic_routing
    processors:
      - set:
          field: "_vmetric.bucket"
          value: "security-events"
          if: "ctx.event_type == 'security'"
      - set:
          field: "_vmetric.bucket"
          value: "application-events"
          if: "ctx.event_type == 'application'"
      - set:
          field: "_vmetric.bucket"
          value: "system-events"
          if: "ctx.event_type == 'system'"

Multiple Buckets with Catch-All

Configuration for routing different log types to specific buckets with a catch-all for unmatched logs:

targets:
  - name: multi_bucket_routing
    type: gcs
    properties:
      key: "GOOG1EXAMPLE1234567890ABCDEFGHIJ"
      secret: "abcdefghijklmnopqrstuvwxyz1234567890ABCD"
      project_id: "my-project-123456"
      region: "us-central1"
      buckets:
        - bucket: "security-logs"
          name: "security-{{.Year}}-{{.Month}}-{{.Day}}.json"
          format: "json"
        - bucket: "application-logs"
          name: "app-{{.Year}}-{{.Month}}-{{.Day}}.json"
          format: "json"
      bucket: "general-logs"
      name: "general-{{.Timestamp}}.json"
      format: "json"

Multiple Buckets with Different Formats

Configuration for distributing data across multiple GCS buckets with different formats:

targets:
  - name: multi_bucket_export
    type: gcs
    properties:
      key: "GOOG1EXAMPLE1234567890ABCDEFGHIJ"
      secret: "abcdefghijklmnopqrstuvwxyz1234567890ABCD"
      project_id: "my-project-123456"
      region: "europe-west1"
      buckets:
        - bucket: "raw-data-archive"
          name: "raw-{{.Year}}-{{.Month}}-{{.Day}}.json"
          format: "multijson"
          compression: "gzip"
        - bucket: "analytics-data"
          name: "analytics-{{.Year}}/{{.Month}}/{{.Day}}/data_{{.Timestamp}}.parquet"
          format: "parquet"
          schema: "<schema definition>"
          compression: "snappy"

Parquet Format

Configuration for daily partitioned Parquet files:

targets:
  - name: parquet_analytics
    type: gcs
    properties:
      key: "GOOG1EXAMPLE1234567890ABCDEFGHIJ"
      secret: "abcdefghijklmnopqrstuvwxyz1234567890ABCD"
      project_id: "my-project-123456"
      region: "us-west1"
      bucket: "analytics-lake"
      name: "events/year={{.Year}}/month={{.Month}}/day={{.Day}}/part-{{.Timestamp}}.parquet"
      format: "parquet"
      schema: "<schema definition>"
      compression: "snappy"
      max_size: 536870912

High Reliability

Configuration with enhanced settings:

targets:
  - name: reliable_gcs
    type: gcs
    pipelines:
      - checkpoint
    properties:
      key: "GOOG1EXAMPLE1234567890ABCDEFGHIJ"
      secret: "abcdefghijklmnopqrstuvwxyz1234567890ABCD"
      project_id: "my-project-123456"
      region: "us-east1"
      bucket: "critical-logs"
      name: "logs-{{.Timestamp}}.json"
      format: "json"
      timeout: 60
      part_size: 10

With Field Normalization

Using field normalization for standard format:

targets:
  - name: normalized_gcs
    type: gcs
    properties:
      key: "GOOG1EXAMPLE1234567890ABCDEFGHIJ"
      secret: "abcdefghijklmnopqrstuvwxyz1234567890ABCD"
      project_id: "my-project-123456"
      region: "europe-west2"
      bucket: "normalized-logs"
      name: "logs-{{.Timestamp}}.json"
      format: "json"
      field_format: "cim"

BigQuery Integration

Configuration optimized for BigQuery data lake:

targets:
  - name: bigquery_ready
    type: gcs
    properties:
      key: "GOOG1EXAMPLE1234567890ABCDEFGHIJ"
      secret: "abcdefghijklmnopqrstuvwxyz1234567890ABCD"
      project_id: "my-project-123456"
      region: "us-central1"
      bucket: "bigquery-staging"
      name: "bq-import/{{.Year}}/{{.Month}}/{{.Day}}/data-{{.Timestamp}}.json"
      format: "json"
      compression: "gzip"
      max_size: 1073741824

Debug Configuration

Configuration with debugging enabled:

targets:
  - name: debug_gcs
    type: gcs
    properties:
      key: "GOOG1EXAMPLE1234567890ABCDEFGHIJ"
      secret: "abcdefghijklmnopqrstuvwxyz1234567890ABCD"
      project_id: "my-project-123456"
      region: "asia-east1"
      bucket: "test-logs"
      name: "test-{{.Timestamp}}.json"
      format: "json"
      debug:
        status: true
        dont_send_logs: true