Checksums and reconciliation

  • Fix
  • Watch 14

Difficulty 4 of 5

Support says some order pages show the wrong total since 1:00. Errors are 0 and p99 is normal. The orders copy has a bad disk, and the ledger is the source of truth. Keep wrong order reads under 5,000 over the run, with no new errors. You have 5 edits.

1:00. Tickets: wrong order totals. Errors 0 percent, p99 flat at 9 ms. Graph: order page errors, flat.

Play level

SQLSQLSQLUsers2,000 req/sPartner apps300 req/sNode API4 vCPU · 4 GBNode API2 vCPU · 2 GBPostgres4 vCPU · 16 GBPostgres2 vCPU · 8 GBMetrics1 vCPU · 1 GB
HTTP/2HTTP/2SQLSQLSQLUsers2,000 req/sPartner ap…300 req/sNode API4 vCPU · 4 GBNode API2 vCPU · 2 GBPostgres4 vCPU · 16 GBPostgres2 vCPU · 8 GBMetrics1 vCPU · 1 GB
The board at the start of the level
A backup and its restoreArrow keys change the backup interval. Tap to change the restore rate.

Backup every 60 minutes · RPO 60 minutes · RTO 11 hours at 100 Mbps

Goals and limits

Corrupted reads
under 5,000
Error rate (Orders)
under 0.1%
p99 latency (Orders)
under 60 ms
Monthly cost
under 170 USD/mo
Edit limit
5
Traffic
2,000 req/s

Concepts

How players did

Player results load from the server.

All levels