Slow initial application load #10447

10 Answer(s)

• 

  0

  AI-Bot created yesterday

  Support Team ABP Agent

  • In an ABP Angular (separated Auth Server) solution, a 20–30s “first response” delay is almost always server cold-start + first-time caches/build steps, not Angular rendering itself. The Angular app blocks on backend calls like OIDC discovery/token and especially GET /api/abp/application-configuration (ABP must load permissions, localization resources, settings, etc.). After that, subsequent navigations become fast because the server and caches are warm.

  • Use this checklist (highest impact first) to reduce first-load and first-visit-per-module slowness:

    1. Run everything in Release mode (backend)

       • Make sure you are not deploying/running the HTTP API Host/Auth Server with Debug settings.
       • Publish with production-oriented settings (helps startup/JIT time):
         • Enable ReadyToRun (and optionally trimming/single-file depending on your constraints).

    2. Avoid expensive “run on startup” operations

       • Ensure you are not applying EF Core migrations automatically on startup in production.
       • If you seed a lot of data/permissions/localization at startup, move it to a one-time migrator or background job.

    3. Warm up the app (solve cold start)

       • If hosted on IIS/Azure/App Service/containers with scale-to-zero, the first request can easily take 20–30 seconds.
       • Use platform features such as:
         • “Always On” / keep-alive
         • app initialization/warmup pings (hit /api/abp/application-configuration once after deployment)
       • If you have multiple services (Auth Server + API Host), warm up both.

    4. Check Redis / distributed cache health & latency (if enabled)

       • ABP heavily uses caching for permissions/localization/config. If Redis is misconfigured, slow, or intermittently unavailable, the first load can degrade badly.
       • Verify Redis is reachable with low latency from both Auth Server and API Host.
       • If Redis is not stable, disable distributed cache temporarily to confirm the bottleneck.

    5. Reduce payload and work in /api/abp/application-configuration

       • First navigation triggers loading:
         • permissions (PermissionStore cache fill)
         • localization dictionaries
         • settings, features, etc.
       • If you have many localization resources or large dictionaries, this endpoint becomes heavier. Reduce unnecessary localization resource registrations/modules if possible.

    6. Angular-side: serve production build

       • For real measurement, test using ng build --configuration production (and serve the built assets), not dev server.

  • Practical way to pinpoint the exact cause (fastest confirmation):

    • Open browser DevTools → Network:
      • Identify which request takes ~20–30s (commonly: OIDC discovery/token, or application-configuration).
    • Check server logs with timing around that endpoint.

  Sources (verified)

  • https://abp.io/community/articles/wa24j28e
  • https://abp.io/docs/latest/framework/ui/angular/quick-start

  ---

  This response was generated by AI. If it didn’t solve your problem, feel free to post a new answer — our support team will jump in to help you soon.

  Save Cancel
• 

  0

  maliming created yesterday

  Support Team Fullstack Developer

  hi

  You can enable debug logs to see which step/request is slow.

  https://abp.io/support/questions/8622/How-to-enable-Debug-logs-for-troubleshoot-problems

  Thanks

  Save Cancel
• 

  0

  BOMSDevTeam created yesterday

  Hi

  I have checked in network tab.

  Thank you

  Save Cancel
• 

  0

  maliming created yesterday

  Support Team Fullstack Developer

  hi

  Can you change the log level and share the logs.txt file? https://abp.io/support/questions/8622/How-to-enable-Debug-logs-for-troubleshoot-problems

  It seems the static PNG file also takes ~2 seconds.

  Thanks.

  Save Cancel
• 

  0

  BOMSDevTeam created yesterday

  Hi

  I have shared the log files via email.

  Thanks

  Save Cancel
• 

  0

  maliming created yesterday

  Support Team Fullstack Developer

  hi

  It seems the cache is delayed. To confirm this, you can disable Redis in your two websites

    "Redis": {
      "IsEnabled": "false",
      "Configuration": "127.0.0.1"
    }
  

  Can you also share a test username &password of https://dev.hxxxxx.com/ website?

  Thanks.

  Save Cancel
• 

  0

  BOMSDevTeam created 16 hours ago

  [maliming] said: hi

  It seems the cache is delayed. To confirm this, you can disable Redis in your two websites

    "Redis": { 
      "IsEnabled": "false", 
      "Configuration": "127.0.0.1" 
    } 
  

  Can you also share a test username &password of https://dev.hxxxxx.com/ website?

  Thanks.

  Hi

  I have shared the latest log files via email.

  Thanks

  Save Cancel
• 

  0

  maliming created 16 hours ago

  Support Team Fullstack Developer

  hi

  I checked your new logs. How many permission in your app?

  The logs show there are over 1600 permissions.

  ---

  Is the application also slow during local development? Or does it only become slow after deployment? What are your server specifications?

  ---

  Can you also share a test username &password of https://dev.hxxxxx.com/ website?

  I will try to reproduce it online.

  Thanks.

  Save Cancel
• 

  0

  BOMSDevTeam created 10 hours ago

  [maliming] said: hi

  I checked your new logs. How many permission in your app?

  The logs show there are over 1600 permissions.

  ---

  Is the application also slow during local development? Or does it only become slow after deployment?
  What are your server specifications?

  ---

  Can you also share a test username &password of https://dev.hxxxxx.com/ website?

  I will try to reproduce it online.

  Thanks.

  Hi

  I have shared the details via email.

  Thanks

  Save Cancel
• 

  0

  maliming created 10 hours ago

  Support Team Fullstack Developer

  hi

  Can you share here? Our Angular team may also check it.

  Thanks.

  Save Cancel