At a glance
This card plots Redis command throughput (instantaneous_ops_per_sec) on one axis against the storefront order rate on the other, over the same minutes. In a healthy store the two lines move together: more shoppers means more orders means more Redis operations. The dangerous pattern is divergence. When Redis operations spike but orders stay flat, work is being done that produces no revenue. That is the fingerprint of a cache stampede (many workers recomputing the same expired key at once) or a bot crawl hammering the cache. The card surfaces that gap while it is open so you can act before it tips into a latency incident.
Calculation
The card samplesinstantaneous_ops_per_sec from INFO stats (Redis’s own rolling estimate of commands per second) and the storefront order rate from the linked connector at the same cadence across the 15-minute window. It then looks for divergence: a statistically meaningful spike in operations that is not accompanied by a comparable spike in orders. The alert fires on that asymmetry, not on high ops alone. High ops during a genuine sales surge is exactly what you want to see; high ops with flat orders is wasted or hostile work. The join is what makes the card actionable: by itself, instantaneous_ops_per_sec cannot tell a Black Friday surge apart from a stampede, because both look like “Redis is busy”.
Worked example
A homeware retailer on BigCommerce caches its category and product pages in Redis with a 60-second TTL. On 22 Apr 26 a popular product page’s cache entry expires at 13:00 just as an influencer post drives a crawl of bots and curious browsers to that exact URL. The platform team has the dual-axis card open.
At 13:00 the cache entry expired and dozens of web workers all missed simultaneously, so they all ran the same expensive origin query and all tried to repopulate the same key at once. Redis operations nearly tripled while orders did not move at all. This is a textbook cache stampede (also called a thundering herd or dogpile). Left alone it cascades: the origin database behind Redis takes the recompute load, command latency rises, and eventually real shoppers feel it.
Sibling cards
Reconciling against the source
Where to look natively:On Amazon ElastiCache: theredis-cli INFO statsforinstantaneous_ops_per_sec, plus the cumulativetotal_commands_processed,keyspace_hitsandkeyspace_missesthat explain a stampede.redis-cli --statfor a live rolling view of ops/sec, memory, and clients refreshed every second.redis-cli MONITOR(use briefly, it is costly) to see the actual commands flooding in and identify the hot key.redis-cli INFO commandstatsfor a per-command call count, useful for proving which command type dominated the spike.
GetTypeCmds, SetTypeCmds, and CacheHits / CacheMisses CloudWatch metrics let you reconstruct the ops mix; aggregate command rate is visible via the engine metrics.
Why our number may legitimately differ:
Known limitations / FAQs
Ops and orders both spiked together. Should I worry? No, that is the healthy pattern and the alert will not fire. Operations rising in step with orders is exactly what a busy, well-behaved store looks like during a genuine surge. The card only flags divergence, where ops climb without a matching order rise. How is a cache stampede different from a bot crawl on this card? Both show ops up with orders flat, so this card flags both. To tell them apart, check siblings: a stampede usually drags Keyspace Hit Rate % down (lots of misses recomputing the same key), while a bot crawl can keep hit rate high but inflates Connected Clients and edge request counts. The fixes differ: TTL jitter and single-flight for stampedes, edge rate-limiting for bots. Why use instantaneous_ops_per_sec rather than counting commands myself?instantaneous_ops_per_sec is the value Redis itself maintains and the one operators recognise, so the card matches what you would see in redis-cli --stat. Computing your own rate from total_commands_processed deltas is possible but introduces sampling-window differences that make reconciliation harder.
We do not cache pages in Redis, only sessions and queues. Is this card still useful?
Yes. An ops spike with flat orders on a session/queue instance often means a runaway job, a retry storm, or a misbehaving consumer rather than a page stampede. The divergence signal is the same; the root cause is different. Pair it with Blocked Clients (BLPOP / BRPOP / WAIT) to spot queue-side trouble.
Can the order rate be zero legitimately while ops are normal?
Yes, overnight or in quiet hours orders can be near zero while background jobs keep Redis ticking over. The alert is tuned to fire on a spike in ops above the trailing baseline, not on a high ops-to-orders ratio in quiet periods, so steady low-order overnight traffic will not trip it.
Can I tune the spike alert threshold?
Yes. The divergence threshold is configurable per profile in the Alert Rules tab. Stores with naturally spiky cache traffic may widen it to reduce noise, while stores that have been bitten by stampedes may tighten it to catch the herd earlier.