In our previous article on GatewayScript concurrency, we explored how to understand and optimize GatewayScript engine performance. But how do you monitor these engines in real-time without constantly logging into the DataPower CLI?

The answer: DataPower’s REST Management Interface. This powerful API allows you to programmatically query GatewayScript status and build automated monitoring solutions.

Why Monitor GatewayScript Availability?

As we discussed in our GatewayScript bottlenecks guide, understanding engine availability is critical for:

  • Detecting bottlenecks before they impact users
  • Capacity planning based on actual usage patterns
  • Performance trending over time
  • Alerting when engines are saturated
  • Troubleshooting performance issues in production

The CLI command show gatewayscript-status is great for ad-hoc checks, but for continuous monitoring, you need automation.

The DataPower REST Management Interface

DataPower provides a comprehensive REST API for management operations. The endpoint we’re interested in is:

GET https://<datapower-host>:5554/mgmt/status/<domain>/GatewayScriptStatus

This endpoint returns the same information as the CLI show gatewayscript-status command, but in JSON format that’s perfect for automation.

Quick Start: Monitoring Script

Here’s a simple bash one-liner to continuously monitor GatewayScript availability:

while true; do 
  curl -k -u admin:password -X GET \
    https://1.2.3.4:5554/mgmt/status/default/GatewayScriptStatus 2>&1 | \
    grep Available; 
  echo; 
done

What This Does:

  • Continuously polls the GatewayScript status endpoint
  • Extracts the “Available” field showing engine availability
  • Displays results in real-time
  • Runs indefinitely until stopped (Ctrl+C)

Sample Output:

    "Available": 8,
    "Available": 8,
    "Available": 8,
    "Available": 8,

Understanding the Response

The full JSON response from the REST API endpoint contains valuable metrics. Here’s the actual output structure:

$ curl -k -u admin:password -X GET https://1.2.3.4:5554/mgmt/status/default/GatewayScriptStatus
{
  "_links": {
    "self": {
      "href": "/mgmt/status/default/GatewayScriptStatus"
    },
    "doc": {
      "href": "/mgmt/docs/status/GatewayScriptStatus"
    }
  },
  "GatewayScriptStatus": {
    "Available": 8,
    "InUse": 0,
    "QueuedWork": 0,
    "Failed": 0
  }
}

Note: The values are returned as integers (not strings), making them easy to parse and compare in monitoring scripts.

Key Fields:

Field Description What to Monitor
Available Total engines configured (integer) Should match CPU core count unless on a physical appliance
InUse Engines currently executing (integer) Watch for approaching Available count
QueuedWork Requests waiting for engines (integer) RED FLAG if > 0
Failed GatewayScript execution errors (integer) Should always be 0

Enhanced Monitoring Script

For production monitoring, you’ll want more detail. Here’s an enhanced version:

#!/bin/bash

# Configuration
DATAPOWER_HOST="9.37.230.250"
DATAPOWER_PORT="5554"
DOMAIN="default"
USERNAME="admin"
PASSWORD="Level2was"
POLL_INTERVAL=5  # seconds

# Colors for output
RED='\033[0;31m'
YELLOW='\033[1;33m'
GREEN='\033[0;32m'
NC='\033[0m' # No Color

echo "Monitoring GatewayScript Status on ${DATAPOWER_HOST}:${DATAPOWER_PORT}"
echo "Domain: ${DOMAIN}"
echo "Poll Interval: ${POLL_INTERVAL}s"
echo "Press Ctrl+C to stop"
echo "----------------------------------------"

while true; do
    # Get current timestamp
    TIMESTAMP=$(date '+%Y-%m-%d %H:%M:%S')
    
    # Query the REST API
    RESPONSE=$(curl -k -s -u ${USERNAME}:${PASSWORD} \
        -X GET \
        "https://${DATAPOWER_HOST}:${DATAPOWER_PORT}/mgmt/status/${DOMAIN}/GatewayScriptStatus")
    
    # Extract values using grep and sed (values are integers, not strings)
    AVAILABLE=$(echo "$RESPONSE" | grep -o '"Available" : [0-9]*' | sed 's/"Available" : //')
    INUSE=$(echo "$RESPONSE" | grep -o '"InUse" : [0-9]*' | sed 's/"InUse" : //')
    QUEUED=$(echo "$RESPONSE" | grep -o '"QueuedWork" : [0-9]*' | sed 's/"QueuedWork" : //')
    FAILURES=$(echo "$RESPONSE" | grep -o '"Failed" : [0-9]*' | sed 's/"Failed" : //')
    

    # Calculate utilization percentage
    if [ -n "$AVAILABLE" ] && [ "$AVAILABLE" -gt 0 ]; then
        UTILIZATION=$((INUSE * 100 / AVAILABLE))
    else
        UTILIZATION=0
    fi
    
    # Determine status color
    if [ "$QUEUED" -gt 0 ]; then
        STATUS_COLOR=$RED
        STATUS="CRITICAL"
    elif [ "$UTILIZATION" -ge 80 ]; then
        STATUS_COLOR=$YELLOW
        STATUS="WARNING"
    else
        STATUS_COLOR=$GREEN
        STATUS="OK"
    fi
    
    # Display status
    echo -e "${TIMESTAMP} | ${STATUS_COLOR}${STATUS}${NC} | Available: ${AVAILABLE} | In-Use: ${INUSE} (${UTILIZATION}%) | Queued: ${QUEUED} | Failures: ${FAILURES}"
    
    # Alert on critical conditions
    if [ "$QUEUED" -gt 0 ]; then
        echo -e "${RED}⚠️  ALERT: ${QUEUED} requests queued - engines saturated!${NC}"
    fi
    
    if [ "$FAILURES" -gt 0 ]; then
        echo -e "${RED}⚠️  ALERT: ${FAILURES} GatewayScript failures detected!${NC}"
    fi
    
    sleep $POLL_INTERVAL
done

Sample Output:

Monitoring GatewayScript Status on 1.2.3.4:5554
Domain: default
Poll Interval: 5s
Press Ctrl+C to stop
----------------------------------------
2026-03-03 14:30:00 | OK | Available: 8 | In-Use: 2 (25%) | Queued: 0 | Failures: 0
2026-03-03 14:30:05 | OK | Available: 8 | In-Use: 3 (37%) | Queued: 0 | Failures: 0
2026-03-03 14:30:10 | WARNING | Available: 8 | In-Use: 7 (87%) | Queued: 0 | Failures: 0
2026-03-03 14:30:15 | CRITICAL | Available: 8 | In-Use: 8 (100%) | Queued: 5 | Failures: 0
⚠️  ALERT: 5 requests queued - engines saturated!

Troubleshooting

Connection Refused

curl: (7) Failed to connect to 1.2.3.4 port 5554: Connection refused

Solutions:

  • Verify REST Management Interface is enabled
  • Check firewall rules
  • Confirm port 5554 is correct (default for REST interface)

Authentication Failed

curl: (22) The requested URL returned error: 401 Unauthorized

Solutions:

  • Verify username and password
  • Check user has appropriate permissions
  • Ensure user is not locked out

Empty Response

Solutions:

  • Verify domain name is correct
  • Check GatewayScript is enabled in the domain
  • Confirm API Gateway service is running

Conclusion

Monitoring GatewayScript availability through the DataPower REST API provides:

  • Real-time visibility into engine utilization
  • Automated alerting for capacity issues
  • Historical data for trend analysis
  • Integration with enterprise monitoring tools

Combined with the capacity planning formulas from our previous article, you now have a complete toolkit for managing GatewayScript performance in production environments.

Additional Resources