🚀 “Our app works fine most of the time, but sometimes it’s just… slow.”
Sound familiar?
Latency is every engineer’s worst nightmare—especially when multi-cloud environments are involved. AWS, Azure, GCP, and others operate with different network architectures, leading to random slowdowns that are hard to predict and debug.
⚠️ Case in Point:
A global fintech company running its frontend on AWS, backend on GCP, and databases on Azure experienced random spikes in API response times. The reason? Hidden packet loss between AWS and GCP.
🔍 In this blog, we’ll break down:
✔️ Why intermittent latency happens in multi-cloud setups
✔️ How to debug latency issues like a pro
✔️ Solutions to fix and optimize multi-cloud performance
⏳ Why Does Multi-Cloud Latency Happen?
Multi-cloud latency is tricky because it’s inconsistent. Some days, your app flies. Other days, it crawls. The usual suspects?
1️⃣ Network Routing Issues
Different cloud providers use different backbone networks. When traffic hops between them, it may take longer routes, causing random delays.
🛑 Real Case:
A healthcare SaaS company had fast traffic between AWS and Azure 80% of the time, but suddenly faced 500ms latency spikes. The culprit? AWS started routing traffic via a different region due to congestion.
✅ Quick Fix:
🔹 Use direct interconnects like AWS Direct Connect or Azure ExpressRoute to bypass public internet traffic.
🔹 Monitor routes using traceroute or MTR to detect inefficient paths.
2️⃣ Hidden Packet Loss & Jitter
Packets may drop or arrive out of order, leading to inconsistent application performance.
🔍 Symptoms:
✔️ Random API timeouts
✔️ VoIP/video calls stuttering
✔️ Spikes in TCP retransmissions
🛑 Real Case:
A logistics company running warehouse tracking software saw API response times jump from 50ms to 600ms randomly. A deep dive with Wireshark showed TCP retransmissions due to packet loss between Azure and GCP.
✅ Quick Fix:
🔹 Run packet capture with Wireshark or TCPDump to identify lost or delayed packets.
🔹 Implement Forward Error Correction (FEC) to recover lost packets.
🔹 Use content delivery networks (CDNs) to optimize data transfer.
3️⃣ Cloud Load Balancers Introducing Latency
Each cloud provider has its own load balancing strategy. Mixing them can cause unexpected delays.
🛑 Real Case:
A media streaming service used AWS ALB for frontend traffic and Google Load Balancer for backend APIs. During peak hours, response times randomly jumped to 1.2s. Reason? The two load balancers had incompatible timeout settings, causing retransmissions.
✅ Quick Fix:
🔹 Align load balancer timeout settings across clouds.
🔹 Consider using a single cross-cloud load balancer like F5 Big-IP or Cloudflare Load Balancer.
4️⃣ Multi-Cloud DNS Resolution Delays
Cloud DNS servers may respond at different speeds, causing inconsistent request latency.
🛑 Real Case:
A fintech company found their multi-cloud APIs had varying response times (150ms-900ms). Investigation showed AWS Route 53 sometimes took longer to resolve Azure-hosted services.
✅ Quick Fix:
🔹 Use Anycast DNS services like Cloudflare or NS1 for faster resolution.
🔹 Preload DNS queries using TTL optimizations to reduce lookup times.
🔍 Debugging Multi-Cloud Latency Like a Pro
🛠️ Step 1: Run a Traceroute to Identify Bottlenecks
💻 Command:
traceroute <destination-IP>
🔍 What to Look For?
✔️ Unexpected route changes
✔️ High RTT (Round-Trip Time) spikes at specific hops
🛠️ Step 2: Use MTR for Real-Time Latency Analysis
💻 Command:
mtr -r -c 100 <destination-IP>
🔍 What to Look For?
✔️ Packet loss at any hop
✔️ Sudden RTT spikes
🛠️ Step 3: Monitor Traffic with Wireshark
💻 Command:
tcpdump -i eth0 port 443 -w capture.pcap
📌 Open the .pcap file in Wireshark to check for:
✔️ Retransmissions
✔️ Dropped packets
✔️ Slow TLS handshake times
🚀 Fixing Multi-Cloud Latency Like a Pro
1️⃣ Optimize Inter-Cloud Routing with Direct Peering
💡 Best Tools:
✅ AWS Direct Connect + Azure ExpressRoute
✅ Google Cloud Interconnect
🔹 Eliminates reliance on public internet
🔹 Reduces unpredictable latency jumps
2️⃣ Implement Anycast Routing for Faster DNS
💡 Best Services:
✅ Cloudflare Anycast DNS
✅ Google Cloud DNS with Geo Routing
🔹 Ensures users hit the fastest DNS resolver
🔹 Reduces random slow lookups
3️⃣ Use Traffic Shaping & Rate Limiting
💡 Best Tools:
✅ NGINX or HAProxy with rate limiting
✅ AWS WAF & Azure Traffic Manager
🔹 Prevents sudden bursts of traffic from overloading specific routes
4️⃣ Implement AI-Based Traffic Optimization
💡 Best AI Tools:
✅ ThousandEyes (Cisco)
✅ Kentik AI-powered NetOps
🔹 Automatically detects & re-routes traffic away from congestion zones
📌 The Future of Multi-Cloud Latency Optimization
🔮 What’s Next?
✅ AI-driven traffic routing will become the default for multi-cloud
✅ Predictive analytics will proactively prevent slowdowns before users notice
✅ 5G & edge computing will further reduce latency for global apps
📌 Bottom Line:
Debugging intermittent latency in multi-cloud is tough, but with the right tools, monitoring, and fixes, you can make your connections blazing fast and reliable.
💬 What’s Your Experience?
Have you faced random multi-cloud slowdowns? Share your insights below! Let’s troubleshoot together. 👇