mohashari

-- event_store schema
CREATE TABLE events (
    id           BIGSERIAL PRIMARY KEY,
    aggregate_id UUID        NOT NULL,
    aggregate_type TEXT      NOT NULL,
    event_type   TEXT        NOT NULL,
    sequence_num INT         NOT NULL,
    payload      JSONB       NOT NULL,
    occurred_at  TIMESTAMPTZ NOT NULL DEFAULT now(),
    UNIQUE (aggregate_id, sequence_num)

mohashari

package sharding

import "fmt"

const shardCount = 4
const rangeSize = 1_000_000

// RangeSharder routes based on numeric ID ranges.
type RangeSharder struct {
	shards []string // DSN per shard

mohashari

func deepHealthHandler(db *sql.DB, cache *redis.Client) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        ctx, cancel := context.WithTimeout(r.Context(), 2*time.Second)
        defer cancel()

        type check struct {
            name string
            fn   func() error
        }

mohashari

# policies/myapp.hcl
path "secret/data/myapp/*" {
  capabilities = ["read", "list"]
}

path "auth/token/renew-self" {
  capabilities = ["update"]
}

path "sys/leases/renew" {

mohashari

apiVersion: apps/v1
kind: Deployment
metadata:
  name: backend-v1
  namespace: production
spec:
  replicas: 2
  selector:
    matchLabels:
      app: backend

mohashari

import asyncio
import httpx

async def fetch_user(client: httpx.AsyncClient, user_id: int) -> dict:
    response = await client.get(f"https://api.internal/users/{user_id}")
    response.raise_for_status()
    return response.json()

async def fetch_permissions(client: httpx.AsyncClient, user_id: int) -> list:
    response = await client.get(f"https://api.internal/permissions/{user_id}")

mohashari

CREATE TABLE events_2026_01 PARTITION OF events
    FOR VALUES FROM ('2026-01-01') TO ('2026-02-01');

CREATE TABLE events_2026_02 PARTITION OF events
    FOR VALUES FROM ('2026-02-01') TO ('2026-03-01');

CREATE TABLE events_2026_03 PARTITION OF events
    FOR VALUES FROM ('2026-03-01') TO ('2026-04-01');

-- Each partition gets its own indexes. PostgreSQL 11+ propagates these

mohashari

#!/usr/bin/env bash
# inject-latency.sh — add 200ms ± 50ms jitter to egress on eth0
# Requires: iproute2, root or CAP_NET_ADMIN

IFACE="${1:-eth0}"
DELAY_MS="${2:-200}"
JITTER_MS="${3:-50}"
DURATION_S="${4:-60}"

echo "[chaos] Injecting ${DELAY_MS}ms ± ${JITTER_MS}ms on ${IFACE} for ${DURATION_S}s"

mohashari

# prometheus/recording_rules.yml
groups:
  - name: slo_availability
    interval: 30s
    rules:
      - record: job:http_requests_total:success_rate5m
        expr: |
          sum(rate(http_requests_total{status!~"5.."}[5m])) by (job)
          /
          sum(rate(http_requests_total[5m])) by (job)

mohashari

CREATE TABLE saga_log (
    id          BIGSERIAL PRIMARY KEY,
    saga_id     UUID        NOT NULL,
    state       TEXT        NOT NULL,
    payload     JSONB,
    created_at  TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE INDEX idx_saga_log_saga_id ON saga_log(saga_id);