company
Japanese marketplace operator whose DBRE team migrated its CoreDB from MySQL to TiDB and published this incident retrospective.
No evidence-backed relationships are recorded.
Mercari's DBRE team overrides its TiDB autoscaling rules by time of day and campaign, and a cluster with a 50% CPU target now averages 44%. Extending the same controller to TiKV storage meant designing around a TiDB Cloud lock that refuses a second scale operation while one is running.
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Sourcegraph's new migration agent scopes a codebase-wide change from one prompt and pauses at every stage by default. Fixing its own red builds is a separate configuration step that needs a token which can read your CI logs.
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Mercari's DBRE team found that on tables with a composite or non-integer primary key, TiDB reads every matching index entry and then sorts. The upstream fix is in master, not in the current LTS.
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Region split size cut region count about 10% and TiKV CPU up to 20%, and the In Memory Engine took 0.5-1.5s queries to roughly 0.1s. Plan cache now runs on one cluster.
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Mercari's DBRE team found the query only after switching a batch read endpoint to TiDB. Query replay had run first and had not flagged it.
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