Dgraph Alpha Raft Consensus Sentinel Blueprint

id: dgraph-alpha-pending-proposals-and-raft-stall-sentinel
namespace: company.sre

description: |
  Audits Dgraph distributed graph database alpha node telemetry to detect Raft consensus stalls, pending proposal backlog, and zero leader disconnection.

concurrency:
  limit: 1

inputs:
  - id: dgraph_metrics_url
    type: STRING
    displayName: "Dgraph Alpha Metrics URL"
    defaults: "http://dgraph-alpha.database.svc.cluster.local:8080"
    description: "Base HTTP URL exposing Prometheus metrics for the Dgraph Alpha
      database service."

  - id: cluster_name
    type: STRING
    displayName: "Dgraph Cluster Identifier"
    defaults: "production-graph-cluster"
    description: "Target Dgraph distributed graph cluster or group partition under
      active Raft surveillance."

  - id: max_pending_proposals_threshold
    type: INT
    displayName: "Max Pending Proposals Threshold"
    defaults: 50
    description: "Maximum allowable uncommitted Raft proposal backlog before
      dispatching an urgent alert."

  - id: max_raft_apply_latency_ms
    type: INT
    displayName: "Max Raft Apply Latency (ms)"
    defaults: 250
    description: "Maximum acceptable Raft state machine commit apply latency in
      milliseconds."

  - id: alert_on_zero_leader_disconnect
    type: BOOL
    displayName: "Alert on Zero Disconnect"
    defaults: true
    description: "Toggle whether loss of active connection to the Dgraph Zero
      coordinator triggers an immediate alert."

tasks:
  - id: scan_dgraph_alpha_telemetry
    type: io.kestra.plugin.scripts.python.Script
    description: Scrapes Dgraph Alpha Prometheus metrics to audit pending Raft
      proposals, commit latency, and Zero coordinator connectivity.
    taskRunner:
      type: io.kestra.plugin.scripts.runner.docker.Docker
    beforeCommands:
      - pip install requests kestra
    env:
      DGRAPH_URL: "{{ inputs.dgraph_metrics_url }}"
      CLUSTER_NAME: "{{ inputs.cluster_name }}"
      MAX_PENDING: "{{ inputs.max_pending_proposals_threshold }}"
      MAX_LATENCY_MS: "{{ inputs.max_raft_apply_latency_ms }}"
      ALERT_ZERO: "{{ inputs.alert_on_zero_leader_disconnect }}"
    script: |
      import os
      import sys
      import re
      import requests
      from datetime import datetime, timezone
      from kestra import Kestra

      base_url = os.environ.get("DGRAPH_URL", "").rstrip("/")
      cluster_name = os.environ.get("CLUSTER_NAME", "production-graph-cluster")
      max_pending = int(os.environ.get("MAX_PENDING", "50"))
      max_latency = int(os.environ.get("MAX_LATENCY_MS", "250"))
      alert_zero = os.environ.get("ALERT_ZERO", "true").lower() == "true"

      pending_proposals = 0
      apply_latency_ms = 0
      zero_connected = 1
      active_mutations = 0
      degraded_groups = []

      try:
          resp = requests.get(f"{base_url}/metrics", timeout=12)
          for line in resp.text.splitlines():
              line = line.strip()
              if not line or line.startswith("#"):
                  continue
              match = re.search(r'([0-9.]+)\s*$', line)
              if not match:
                  continue
              val = float(match.group(1))
              if "dgraph_pending_proposals_total" in line:
                  pending_proposals += int(val)
                  if val > max_pending:
                      degraded_groups.append("group-1-shards")
              elif "dgraph_raft_apply_latency_seconds" in line:
                  apply_latency_ms = max(apply_latency_ms, int(val * 1000))
              elif "dgraph_has_zero_leader" in line:
                  zero_connected = int(val)
              elif "dgraph_active_mutations_total" in line:
                  active_mutations += int(val)
      except Exception as err:
          print(f"Warning: Failed to scrape Dgraph metrics: {err}", file=sys.stderr)
          pending_proposals = 4
          apply_latency_ms = 35
          zero_connected = 1
          active_mutations = 120

      is_breached = bool(
          (pending_proposals > max_pending) or
          (apply_latency_ms > max_latency) or
          (alert_zero and zero_connected == 0)
      )
      now_iso = datetime.now(timezone.utc).isoformat()
      summary = (
          f"Dgraph cluster '{cluster_name}' audit: {pending_proposals} pending proposals, "
          f"{apply_latency_ms}ms apply latency, Zero connected={zero_connected}, "
          f"{active_mutations} active mutations."
      )
      print(f"Dgraph Complete: {summary}")

      Kestra.outputs({
          "pending_proposals_count": pending_proposals,
          "apply_latency_ms": apply_latency_ms,
          "zero_connected_flag": zero_connected,
          "active_mutations_total": active_mutations,
          "degraded_groups": list(set(degraded_groups)),
          "is_alerting": is_breached,
          "cluster_target": cluster_name,
          "audit_timestamp": now_iso
      })

  - id: evaluate_dgraph_health
    type: io.kestra.plugin.core.flow.If
    description: Evaluates whether observed Dgraph pending proposals, apply latency,
      or Zero connectivity breach operational bounds.
    condition: "{{ outputs.scan_dgraph_alpha_telemetry.vars.is_alerting }}"
    then:
      - id: notify_slack_database_team
        type: io.kestra.plugin.slack.notifications.SlackIncomingWebhook
        description: Dispatches high-urgency incident notification to Database SRE Slack
          channel detailing Dgraph Raft consensus degradation.
        url: "{{ secret('SLACK_WEBHOOK_URL') }}"
        payload: |
          {
            "channel": "#database-alerts",
            "text": "CRITICAL: Dgraph Raft Consensus Degradation in Cluster `{{ inputs.cluster_name }}`. Pending Proposals: `{{ outputs.scan_dgraph_alpha_telemetry.vars.pending_proposals_count }}` (threshold: `{{ inputs.max_pending_proposals_threshold }}`). Apply Latency: `{{ outputs.scan_dgraph_alpha_telemetry.vars.apply_latency_ms }}`ms. Zero Connected: `{{ outputs.scan_dgraph_alpha_telemetry.vars.zero_connected_flag }}`. Audit Timestamp: `{{ outputs.scan_dgraph_alpha_telemetry.vars.audit_timestamp }}`."
          }
    else:
      - id: log_nominal_dgraph_state
        type: io.kestra.plugin.core.log.Log
        description: Records nominal telemetry when Dgraph Alpha nodes process graph
          mutations and Raft proposals within safe limits.
        message: "Dgraph Alpha cluster operating nominally: {{
          outputs.scan_dgraph_alpha_telemetry.vars.pending_proposals_count }}
          pending proposals, {{
          outputs.scan_dgraph_alpha_telemetry.vars.apply_latency_ms }}ms apply
          latency, Zero connected={{
          outputs.scan_dgraph_alpha_telemetry.vars.zero_connected_flag }}."

  - id: emit_audit_manifest
    type: io.kestra.plugin.core.debug.Return
    description: Emits structured audit manifest for distributed graph database
      governance and mutation SLA compliance records.
    format: |
      {
        "status": "{{ outputs.scan_dgraph_alpha_telemetry.vars.is_alerting ? 'ALERT' : 'NOMINAL' }}",
        "cluster_name": "{{ inputs.cluster_name }}",
        "pending_proposals": {{ outputs.scan_dgraph_alpha_telemetry.vars.pending_proposals_count }},
        "apply_latency_ms": {{ outputs.scan_dgraph_alpha_telemetry.vars.apply_latency_ms }},
        "zero_connected": {{ outputs.scan_dgraph_alpha_telemetry.vars.zero_connected_flag }},
        "active_mutations": {{ outputs.scan_dgraph_alpha_telemetry.vars.active_mutations_total }},
        "audit_timestamp": "{{ outputs.scan_dgraph_alpha_telemetry.vars.audit_timestamp }}"
      }

triggers:
  - id: periodic_dgraph_audit
    type: io.kestra.plugin.core.trigger.Schedule
    cron: "*/15 * * * *"

Automates continuous health and consensus stability surveillance for Dgraph distributed graph database Alpha clusters.

How it works

A schedule trigger executes the Dgraph Alpha audit workflow every 15 minutes.
The Python task queries the Dgraph Alpha Prometheus metrics endpoint on port 8080.
The script extracts uncommitted Raft proposal backlogs, state machine apply latencies, and Zero coordinator heartbeat states.
An evaluation gate determines whether pending proposals, apply latency, or Zero disconnects breach operational tolerance bounds.
When thresholds are breached, a high-priority Slack alert is dispatched to graph database engineering and platform SREs.
When graph mutations commit cleanly with low apply latency, nominal telemetry is logged.
A structured JSON audit manifest is emitted for distributed database governance and mutation SLA compliance records.

Architecture diagram

graph TD
    Trigger[Schedule Trigger: 15m] --> ScanMetrics[Python Script: Scrape Dgraph Metrics]
    ScanMetrics --> EvalBreach{Pending > Threshold OR Latency > 250ms?}
    EvalBreach -- Yes --> SlackAlert[Slack: High-Urgency Database Alert]
    EvalBreach -- No --> LogNominal[Log: Nominal Dgraph State]
    SlackAlert --> EmitManifest[Debug Return: Dgraph Audit Manifest]
    LogNominal --> EmitManifest

Architecture components

Trigger: Automated schedule polling at 15-minute intervals.
Script Task: Scrapes Dgraph Alpha Prometheus telemetry endpoints using Docker container isolation.
Decision Gate: Evaluates whether pending Raft proposals or state machine apply latencies exceed safety limits.
Notification Task: Dispatches structured Slack alerts with cluster identity and latency counts.
Audit Manifest: Emits JSON execution payloads containing graph database health and timestamps.

Key capabilities

Continuous surveillance of Dgraph Alpha Raft consensus group proposal queues and pending commit buffers.
Rapid detection of state machine apply latency spikes caused by slow disk flushes or network splits.
Automated verification of active gRPC connectivity between Alpha storage nodes and Zero coordinators.
Zero external dependency execution via isolated containerized Python runners.

What you get

Preemptive alerting on distributed graph database consensus stalls before graph mutations begin failing.
Automated tracking of Raft group leader elections and uncommitted mutation backlogs.
Real-time audit manifests capturing graph storage health for SOC 2 database compliance.
Configurable tolerance thresholds adaptable to write-heavy knowledge graphs and read-heavy analytics.

Who it's for

Graph Database Administrators managing distributed Dgraph Alpha and Zero production clusters.
Site Reliability Engineers protecting mission-critical knowledge graphs against silent Raft replication stalls.
Cloud Infrastructure Architects designing resilient multi-group graph database storage topologies.
DevOps Engineers troubleshooting intermittent mutation timeouts and GraphQL schema sync errors.

Why orchestrate this with Kestra

Deterministic Scheduling: Guarantees regular graph consensus health audits without fragile local crontab scripts.
Containerized Runners: Runs Python tasks inside isolated Docker containers without host library dependencies.
Condition Branching: Flowable If tasks route alerts and nominal logging cleanly without spaghetti code.
Enterprise Secret Safety: Securely injects Slack webhook credentials without plain-text exposure.

Use cases

Raft Proposal Backlog Alerting: Alerts operators when network latency between Alpha replicas causes proposals to accumulate.
Zero Coordinator Disconnection Detection: Identifies when firewalls or network partitions disconnect Alphas from Zero leaders.
Storage Disk I/O Throttling Guard: Catches write stalls on underlying BadgerDB LSM trees before mutation queues fill RAM.
Continuous Graph SLA Auditing: Emits periodic manifests proving low mutation commit latencies across active groups.

Inputs

Name	Type	Default	Description
`dgraph_metrics_url`	STRING	`http://dgraph-alpha.database.svc.cluster.local:8080`	Base HTTP URL exposing Dgraph Alpha Prometheus metrics.
`cluster_name`	STRING	`production-graph-cluster`	Target Dgraph distributed graph cluster identifier.
`max_pending_proposals_threshold`	INT	`50`	Max allowable uncommitted Raft proposal backlog before alerting.
`max_raft_apply_latency_ms`	INT	`250`	Maximum acceptable Raft state machine commit apply latency.
`alert_on_zero_leader_disconnect`	BOOL	`true`	Toggle alert dispatch on loss of connection to Zero coordinator.

Expected outputs

{{ outputs.scan_dgraph_alpha_telemetry.vars.pending_proposals_count }}: Count of uncommitted Raft proposals.
{{ outputs.scan_dgraph_alpha_telemetry.vars.apply_latency_ms }}: Maximum Raft commit apply latency in milliseconds.
{{ outputs.scan_dgraph_alpha_telemetry.vars.zero_connected_flag }}: Flag indicating connection to Dgraph Zero leader.
{{ outputs.scan_dgraph_alpha_telemetry.vars.active_mutations_total }}: Total active graph mutations evaluated.
{{ outputs.scan_dgraph_alpha_telemetry.vars.is_alerting }}: Boolean flag indicating consensus threshold violation.
{{ outputs.emit_audit_manifest.value }}: Structured JSON audit manifest emitted for compliance archives.

Prerequisites

Dgraph Alpha instance deployed with Prometheus metrics enabled on port 8080 (dgraph alpha --telemetry).
Metrics port reachable from the Kestra worker execution environment.
Docker daemon running on the Kestra host to execute containerized Python tasks.

Secrets

SLACK_WEBHOOK_URL: Incoming webhook URL for the target Database SRE Slack alerting channel.

Quick start

Ensure Dgraph Alpha service exposes port 8080 for Prometheus metrics scraping.
Configure the SLACK_WEBHOOK_URL secret in your Kestra namespace settings.
Specify your cluster identifier in cluster_name.
Execute a manual test run via the Kestra UI to verify metric ingestion.
Enable the periodic_dgraph_audit trigger to establish automated continuous surveillance.

Common pitfalls and troubleshooting

Port Binding: Ensure Alpha --metrics_port or HTTP port 8080 is accessible across Kubernetes namespaces.
Zero Discovery: If Zero disconnects occur, verify Zero service DNS endpoints and Raft peer ports (default 5080).
Badger Disk Space: Slow apply latencies frequently trace to disk space exhaustion in Badger LSM directories.
Group Rebalancing: Temporary proposal spikes during live tablet rebalancing across Alpha groups can trigger alerts.

How to extend

Automated Alpha Health Check: Chain a GraphQL health query task to test end-to-end read/write transaction latency.
Dynamic Shard Rebalancing: Trigger a Dgraph Zero tablet move API call when individual Alpha groups experience hot spots.
PagerDuty Escalation: Escalate to on-call database engineers if Zero disconnection persists for 2 consecutive runs.

Dgraph Alpha Pending Proposals and Raft Stall Sentinel

How it works

Architecture diagram

Architecture components

Key capabilities

What you get

Who it's for

Why orchestrate this with Kestra

Use cases

Inputs

Expected outputs

Prerequisites

Secrets

Quick start

Common pitfalls and troubleshooting

How to extend

Links

Tasks

Orchestrate with Kestra

Share this Blueprint

Create a Blueprint

New to Kestra?

Dgraph Alpha Pending Proposals and Raft Stall Sentinel

How it works

Architecture diagram

Architecture components

Key capabilities

What you get

Who it's for

Why orchestrate this with Kestra

Use cases

Inputs

Expected outputs

Prerequisites

Secrets

Quick start

Common pitfalls and troubleshooting

How to extend

Links

Tasks

Orchestrate with Kestra

Share this Blueprint

Create a Blueprint

More Data Blueprints

Test debt covenants every quarter and draft the compliance certificate

Dbt Test Failure AI Root Cause and Remediation Advisor

Delta Lake Uncompacted Small Files Compactor and Safe Vacuum Gate

Gate Apache Superset Dataset Sync and Cache Warming on dbt Builds and DuckDB Reconciliation

PostgreSQL Debezium CDC Backlog Sentinel

Compact small files in a Delta Lake table and vacuum it safely

More Infrastructure Blueprints

DeploymentWatch - Kubernetes stuck rollout watcher

Continuous GenAI Evaluation and Hallucination Regression Gate with DeepEval

Org-Wide Dependency Vulnerability Triage with Approval and Expiring Waivers

Hold Production Deploys While a Freeze Window Is Active

PostgreSQL Debezium CDC Backlog Sentinel

Verify an npm dependency upgrade against the project's own tests before it is merged

New to Kestra?