sentinels

They serve an important purpose as sentinels but on this one the evidence is a mile wide and an inch deep.

We feel that Sentinels are clearly an afterthought, hacked on the side of Redis to tick the failover box.

Thought of a more recent example, just like the upgraded sentinels in Xmen, days of future past.

All of these cases may require the use of sentinels / additional checks to implement.

It and The Sentinels by James Layton were my two favorite reads this year.

So if you consider Sentinel + Redis as an unique system, Sentinel guarantees that every given partition of Sentinels agree about the configuration (as a general case when all the partitions heal, all Sentinels will agree).

There are so many issues with sentinels they really are still a hacked together afterthought just to try and tick off a few reliability boxes.

What I hate most, is people using unusual but cromulent values as sentinels.

I would be most interested in how you manage failover, sentinels are probably the worst failover mechanism I've used in a long time.

Bradley is pretty extreme:) It's not necessarily a bad thing to have sentinels out on the fringes, like RMS and Bradley, to remind us not to get lost.

I can't believe sentinels still re-write their own config in /etc.

I get what you're saying, but even when sentinels are used inside a function, returning a -1 to the caller seems like a pretty bad API.

The end of the article summarizes by stating "even if the Iranian Sentinels fly on the schedule, they probably won’t be truly stealthy." The intent of the RQ-170 is the be stealthy, a copy that's not stealthy isn't a copy.

A book I recently read and really enjoyed was The Sentinels.

The distributed system that you obtain summing Sentinel + Redis data stores is an eventually consistent system where the merge function is using the data set of the master with the greatest configEpoch (the latest promoted by the majority of Sentinels).