Arbitrum MEV: Latency Pitfalls & Routing Tips

Overview

Avoid throttled endpoints, measure variance, and balance filters to maintain recall.

Key points

• Reliable WSS with low median and variance.
• Private bundles where available; fallback with caps.
• Liquidity checks and router allowlists.

Checklist

• Backpressure handling enabled.
• Slippage and gas caps set.
• Session budget defined.

Next steps

Try the WSS Latency Test tool and review the Flashbots guide.

How to benchmark Arbitrum endpoints

Start with two providers in different regions. Run sustained 60-second tests using the FRB WSS Latency Tool, record p50/p95 latency, and log packet loss. Arbitrum sequencer bursts reward teams that react fast; if variance climbs above 40 ms, rotate to your standby endpoint before inclusion dips.

1. Capture baseline metrics at the start of every session.
2. Feed results into Ops Pulse so the desk can correlate mistakes with latency spikes.
3. Trigger alerts whenever throttling or rate limits appear, then pause risky routes.

Routing workflow

1. Stage changes in simulation for 24 hours.
2. Promote to canary size with strict budget caps.
3. Only move to full size after two clean sessions and documented approvals.

Links to keep handy:

• Chain MEV Hub for cross-network playbooks.
• FRB Support when a relay or endpoint degrades.

Build a latency dashboard the desk can trust

Every rollout should include a lightweight dashboard that mirrors Ops Pulse. Track:

• Endpoint health: open / first-message times, throttling counts, API key rotation dates.
• Relay status: Flashbots vs Builder0x69 inclusion, rejection reasons, refund ratios.
• Bundle depth: transactions per bundle, gas multipliers, and which guardrails triggered.

Pipe the raw data into your preferred stack (Grafana, Looker, FRB export) and keep screenshots in the Knowledge Base so newcomers can orient quickly.

Incident response drill

When something breaks mid-session:

1. Pause & capture context. Freeze the route, snapshot Ops Pulse, and note the block height.
2. Diagnose rapidly. Compare latency charts against builder health; rotate instead of halting everything if a single builder is degraded.
3. Document & communicate. Post a short update in ops chat plus a ticket linking to latency screenshots and refund stats.
4. Review before restart. Confirm guardrails are intact, warm up the standby endpoint, and resume only after a second operator signs off.

Sample runbook entry

Date: 2025-11-28
Route: Arbitrum Backrun – Stable pools
Variance alert: p95 jumped from 118 ms to 207 ms (QuickNode FRA)
Action: Rotated to Alchemy SIN, downshifted bundle size to 0.6×, refund guard trip set to 2/30
Result: Inclusion recovered to 63% within four blocks; documenting for weekly review.
Copy

Archive one entry per incident so audits can reconstruct decisions quickly.

FAQ

How often should I rotate endpoints?
Weekly at minimum; immediately after sustained variance spikes.

What gas multiplier works best?
Start with 1.1× your modeled value, then let refund telemetry inform adjustments.

Can I mix private and public submissions?
Yes, but keep public PGAs for micro-canaries and log every attempt for compliance.

How many builders should I monitor?
At least three: your primary Flashbots lane, a secondary builder, and one research relay you can graduate later.

What do I share with compliance?
Provide the latency dashboard snapshot, refund statistics, and the runbook entries above—numbers plus narrative shorten reviews dramatically.