Heroku R14 Memory Quota Exceeded Error

How to fix it

Try these in order — the most common fix is first.

1. 1. Limit process count with WEB_CONCURRENCY

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   1. Run heroku config:set WEB_MEMORY=<MB per process> so Heroku computes WEB_CONCURRENCY
   2. Or set WEB_CONCURRENCY manually (for example 1 or 2 on a 512 MB dyno)
   3. Do not size workers by CPU count
   Did this fix it? Yes No

2. 2. Cap the Node heap on older Node

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   1. On Node below 12 set the Procfile to: web: node --optimize_for_size --max_old_space_size=460 server.js (for a 512 MB dyno)
   2. Node 12 and newer base the limit on available memory, so this is usually not needed
   Did this fix it? Yes No

3. 3. Look for a leak

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   1. Check whether memory climbs steadily without more traffic, which points to a leak or a recent code change
   2. Take heap snapshots with node --inspect locally or heroku ps:forward on staging
   3. Update dependencies and Node/Ruby version
   Did this fix it? Yes No

4. 4. Restart as a stopgap

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   1. heroku ps:restart -a <app> clears memory until it grows again
   2. Heroku also restarts dynos daily
   Did this fix it? Yes No

5. 5. Move to a bigger dyno

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   1. Standard-2X has 1 GB, Performance-M has 2.5 GB
   2. Run heroku ps:type standard-2x -a <app>
   3. Note the cost: Standard-2X is $50/month
   Did this fix it? Yes No

Symptoms

Logs show Error R14 (Memory quota exceeded) with memory_total above the quota; the app gets slow, then may restart with R15.

Why it happens

• Too many web processes or threads for the dyno's RAM
• A memory leak that grows with uptime
• Large in-memory data or caches
• Node heap limit set higher than the dyno
• Eco, Basic and Standard-1X dynos only have 512 MB

This guide also covers

• heroku r14 memory quota exceeded
• heroku r14 error
• heroku memory quota vastly exceeded r15
• heroku out of memory

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