Dead-letter queue has no size cap — can grow unbounded in Redis

[hman38705]

Labels: reliability, email

Priority: Medium

Description

src/email/queue.rs pushes failed jobs to a Redis dead-letter queue list without any length limit. A sustained email failure (e.g., invalid SendGrid key) will fill the DLQ indefinitely, consuming Redis memory until eviction or OOM.

Acceptance Criteria

• Add a configurable EMAIL_DLQ_MAX_SIZE (default 1000) using Redis LTRIM after each push to cap the list
• When the cap is reached, emit a log.error and increment a dead_letter_queue_overflow_total counter
• Add a Prometheus alert rule firing when DLQ size exceeds 80% of the cap
• Add a test that overflows the cap and verifies the counter increments and oldest item is dropped

[karanjadavi]

@karanjadavi has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

can i work on this issue

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[edwarddavid929-png]

@edwarddavid929-png has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

i would like to work on this project

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