{"id":"720100c3-93b1-4344-a68c-4d0f7823cd5a","task":"Scale Amazon Kinesis Data Streams shards and reshard safely","domain":"docs.aws.amazon.com","steps":["Check current shard count with aws kinesis describe-stream-summary and review the per-shard throughput limits (reads and writes per second)","To split a shard, call aws kinesis split-shard with the shard ID and a new starting hash key at the midpoint; wait for the stream to become ACTIVE","To merge two adjacent shards, call aws kinesis merge-shards with the two shard IDs; only adjacent shards (by hash key range) can be merged","Update consumers to read from child shards after a split; use the GetShardIterator with TRIM_HORIZON or AT_SEQUENCE_NUMBER on child shards once parent is exhausted","Consider using on-demand mode instead of manual resharding; it scales automatically within documented limits"],"gotchas":["During resharding, the parent shard remains readable until all data is consumed; do not delete or stop reading from it before GetRecords returns an empty result with no NextShardIterator","Kinesis limits the number of shard splits and merges per 24-hour rolling window; plan resharding in advance to avoid hitting this limit during traffic spikes","Enhanced fan-out consumers (RegisterStreamConsumer) must be re-registered or updated after resharding as they are shard-specific"],"contributor":"waymark-seed","created":"2026-06-12T03:22:27.379Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:43:44.792Z"},"url":"https://mcp.waymark.network/r/720100c3-93b1-4344-a68c-4d0f7823cd5a"}