PGBouncer + Postgres dashboard

pgbouncer-watch.sh

#!/bin/bash
# PGBouncer + Postgres dashboard
#
# Usage:
#   ./pgbouncer_stats.sh                          # uses env vars or defaults
#   ./pgbouncer_stats.sh --watch                  # refresh every 5s
#   ./pgbouncer_stats.sh --watch 2                # refresh every 2s
#
# Environment variables (all optional):
#   PGB_HOST        PGBouncer host            (default: localhost)
#   PGB_PORT        PGBouncer port            (default: 6432)
#   PGB_USER        PGBouncer admin user      (default: postgres)
#   PGB_PASSWORD    PGBouncer admin password   (default: pg_password)
#   PG_HOST         Postgres host             (default: localhost)
#   PG_PORT         Postgres port             (default: 5432)
#   PG_USER         Postgres user             (default: convoy)
#   PG_PASSWORD     Postgres password         (default: pg_password)
#   PG_DATABASE     Postgres database         (default: convoy)

set -euo pipefail

# Config with defaults
PGB_HOST="${PGB_HOST:-localhost}"
PGB_PORT="${PGB_PORT:-6432}"
PGB_USER="${PGB_USER:-postgres}"
PGB_PASSWORD="${PGB_PASSWORD:-pg_password}"

PG_HOST="${PG_HOST:-localhost}"
PG_PORT="${PG_PORT:-6432}"
PG_USER="${PG_USER:-convoy}"
PG_PASSWORD="${PG_PASSWORD:-pg_password}"
PG_DATABASE="${PG_DATABASE:-convoy}"

# Auto-detect: use local psql if available, otherwise try docker
PGB_DOCKER="${PGB_DOCKER:-local-pgbouncer-1}"
PG_DOCKER="${PG_DOCKER:-local-postgres-1}"

pgb_query() {
  if command -v psql &>/dev/null; then
    PGPASSWORD="$PGB_PASSWORD" psql -h "$PGB_HOST" -p "$PGB_PORT" -U "$PGB_USER" pgbouncer -t -A -F"|" -c "$1" 2>/dev/null
  else
    docker exec "$PGB_DOCKER" sh -c "PGPASSWORD=$PGB_PASSWORD psql -h 127.0.0.1 -p 6432 -U $PGB_USER pgbouncer -t -A -F\"|\" -c \"$1\"" 2>/dev/null
  fi
}

pg_query() {
  if command -v psql &>/dev/null; then
    PGPASSWORD="$PG_PASSWORD" psql -h "$PG_HOST" -p "$PG_PORT" -U "$PG_USER" -d "$PG_DATABASE" -t -A -c "$1" 2>/dev/null
  else
    docker exec "$PG_DOCKER" psql -U "$PG_USER" -d "$PG_DATABASE" -t -A -c "$1" 2>/dev/null
  fi
}

fmt() { printf "%'d" "$1" 2>/dev/null || echo "$1"; }

fmt_us() {
  local us=$1
  if [ "$us" -ge 1000000 ] 2>/dev/null; then
    echo "$((us / 1000000)).$((us % 1000000 / 1000))s"
  elif [ "$us" -ge 1000 ] 2>/dev/null; then
    echo "$((us / 1000))ms"
  else
    echo "${us}us"
  fi
}

run_once() {
  # Fetch stats
  POOLS=$(pgb_query "SHOW POOLS;" | grep -v "^pgbouncer" | head -1)
  STATS=$(pgb_query "SHOW STATS;" | grep -v "^pgbouncer" | head -1)
  PG_BACKENDS=$(pg_query "SELECT count(*), count(*) FILTER (WHERE state='active'), count(*) FILTER (WHERE state='idle') FROM pg_stat_activity WHERE backend_type='client backend';")
  PG_MAX=$(pg_query "SHOW max_connections;")

  if [ -z "$POOLS" ]; then
    echo "ERROR: Could not connect to PGBouncer at $PGB_HOST:$PGB_PORT"
    echo "Set PGB_HOST, PGB_PORT, PGB_USER, PGB_PASSWORD env vars."
    exit 1
  fi

  if [ -z "$PG_BACKENDS" ]; then
    echo "ERROR: Could not connect to Postgres at $PG_HOST:$PG_PORT"
    echo "Set PG_HOST, PG_PORT, PG_USER, PG_PASSWORD, PG_DATABASE env vars."
    exit 1
  fi

  # Parse PGBouncer pools
  CL_ACTIVE=$(echo "$POOLS" | cut -d'|' -f3)
  CL_WAITING=$(echo "$POOLS" | cut -d'|' -f4)
  SV_ACTIVE=$(echo "$POOLS" | cut -d'|' -f7)
  SV_IDLE=$(echo "$POOLS" | cut -d'|' -f10)
  MAXWAIT=$(echo "$POOLS" | cut -d'|' -f14)
  POOL_MODE=$(echo "$POOLS" | cut -d'|' -f16 | tr -d ' ')

  # Parse PGBouncer stats
  TOTAL_XCT=$(echo "$STATS" | cut -d'|' -f3)
  TOTAL_QUERY=$(echo "$STATS" | cut -d'|' -f4)
  AVG_QUERY_US=$(echo "$STATS" | cut -d'|' -f14)
  TOTAL_WAIT_US=$(echo "$STATS" | cut -d'|' -f9)

  # Parse Postgres
  PG_TOTAL=$(echo "$PG_BACKENDS" | cut -d'|' -f1)
  PG_ACTIVE=$(echo "$PG_BACKENDS" | cut -d'|' -f2)
  PG_IDLE=$(echo "$PG_BACKENDS" | cut -d'|' -f3)

  # Multiplexing ratio
  SV_TOTAL=$((SV_ACTIVE + SV_IDLE))
  if [ "$SV_TOTAL" -gt 0 ] 2>/dev/null; then
    RATIO="$CL_ACTIVE clients -> $SV_TOTAL PG backends ($PG_MAX max)"
  else
    RATIO="$CL_ACTIVE clients -> $PG_TOTAL PG backends ($PG_MAX max)"
  fi

  echo ""
  echo "=== PGBouncer + Postgres Dashboard === ($(date '+%H:%M:%S'))"
  echo ""
  printf "%-38s %s\n" "Pool mode:" "$POOL_MODE"
  printf "%-38s %s\n" "Client connections (active):" "$CL_ACTIVE"
  printf "%-38s %s\n" "Client connections (waiting):" "$CL_WAITING"
  printf "%-38s %s\n" "Max wait (seconds):" "$MAXWAIT"
  printf "%-38s %s\n" "Server connections (active):" "$SV_ACTIVE"
  printf "%-38s %s\n" "Server connections (idle):" "$SV_IDLE"
  echo ""
  printf "%-38s %s\n" "Total transactions:" "$(fmt $TOTAL_XCT)"
  printf "%-38s %s\n" "Total queries:" "$(fmt $TOTAL_QUERY)"
  printf "%-38s %s\n" "Avg query time:" "$(fmt_us $AVG_QUERY_US)"
  printf "%-38s %s\n" "Total wait time:" "$(fmt_us $TOTAL_WAIT_US)"
  echo ""
  printf "%-38s %s\n" "Postgres backend connections:" "$PG_TOTAL"
  printf "%-38s %s\n" "Postgres active backends:" "$PG_ACTIVE"
  printf "%-38s %s\n" "Postgres idle backends:" "$PG_IDLE"
  printf "%-38s %s\n" "Postgres max_connections:" "$PG_MAX"
  echo ""
  printf "%-38s %s\n" "Connection multiplexing:" "$RATIO"
  echo ""
}

# Handle --watch mode
if [ "${1:-}" = "--watch" ]; then
  INTERVAL="${2:-5}"
  while true; do
    clear
    run_once
    sleep "$INTERVAL"
  done
else
  run_once
fi