Reply to Aphyr attack on Redis Sentinel • Hacker News Board

Re: Reply to Aphyr attack on Redis Sentinel

#11

Post by Glyptodon » Mon, May 20, 2013, 4:10 PM UTC

antirez wrote: post #9

Glyptodon wrote: post #8

Redis is one of those things I both love and love to hate. I've had good results using Redis as a lock server, but I live in (perhaps misplaced) fear of a client hanging or crashing leaving a lock stranded. Not that this is really Redis's problem.

Hello, you can easily mount a lock that auto-releases itself after some timeout using the new (2.6.13) extended SET command (see http://redis.io/commands/set ) or simply a Lua script.

Since the jobs we're locking can have somewhat inconsistent times we're actually using an implementation where the tasks can get a lock with a time limit and can extend their lock so long as they still have it, so they do potentially auto-release.

Even given this, bad lock timing (not that likely) or a crash (more likely) could let inconsistency in.

Shrugs

Like I said, my problem is not really Redis's. If I can't trust everything that uses a lock not to crash 99.99% of the time I should really be looking at our jobs and not at Redis.

Even then, though, it's probably more a matter of me not trusting things than it is said things not actually being trustworthy.

Re: Reply to Aphyr attack on Redis Sentinel

#12

Post by tptacek » Mon, May 20, 2013, 4:11 PM UTC

undoware wrote: post #10

I'm frustrated that when the HN editors deduped the original story, they apparently deleted ALL the instances, leaving only this one. I wanted to read the discussion on the subject of Aphyr's research, not Antirez' response. It looks bad, HN. We all know that VMWare is litigious as (try looking up benchmarks sometime.) But to (presumably) cave so quickly and effortlessly suggests... well, I'm not sure. The other poss…

It is extremely unlikely that any pressure was put on the HN admins by VMWare or anyone else to get stories scrubbed. It's almost as unlikely that VMWare gives a shit about stories about Redis.

Re: Reply to Aphyr attack on Redis Sentinel

#13

Post by antirez » Mon, May 20, 2013, 4:14 PM UTC

undoware wrote: post #10

I'm frustrated that when the HN editors deduped the original story, they apparently deleted ALL the instances, leaving only this one. I wanted to read the discussion on the subject of Aphyr's research, not Antirez' response. It looks bad, HN. We all know that VMWare is litigious as (try looking up benchmarks sometime.) But to (presumably) cave so quickly and effortlessly suggests... well, I'm not sure. The other poss…

Hello,

1) I no longer work for VMware, but Pivotal. Redis is open source and copyright is of the original guys that wrote the code: I, Pieter Noordhuis, other contributors.

2) I posted the link to the original article in the first very lines of my reply. Actually thanks to my reply the exposure the Aphyr research had about Redis is the greatest, compared to the other data stores mentioned. I publicly said thank you to Aphyr on Twitter, and posted its blog post.

So I really don't understand your theories here.

Re: Reply to Aphyr attack on Redis Sentinel

#14

Post by aphyr » Mon, May 20, 2013, 4:16 PM UTC

undoware wrote: post #10

I'm frustrated that when the HN editors deduped the original story, they apparently deleted ALL the instances, leaving only this one. I wanted to read the discussion on the subject of Aphyr's research, not Antirez' response. It looks bad, HN. We all know that VMWare is litigious as (try looking up benchmarks sometime.) But to (presumably) cave so quickly and effortlessly suggests... well, I'm not sure. The other poss…

https://www.hnsearch.com/search#request/all&q=aphyr.com

HN stories on my original posts are still there, as far as I can tell. They just never hit frontpage.

Re: Reply to Aphyr attack on Redis Sentinel

#15

Post by antirez » Mon, May 20, 2013, 4:18 PM UTC

aphyr wrote: post #14

undoware wrote: post #10

I'm frustrated that when the HN editors deduped the original story, they apparently deleted ALL the instances, leaving only this one. I wanted to read the discussion on the subject of Aphyr's research, not Antirez' response. It looks bad, HN. We all know that VMWare is litigious as (try looking up benchmarks sometime.) But to (presumably) cave so quickly and effortlessly suggests... well, I'm not sure. The other poss…

https://www.hnsearch.com/search#request/all&q=aphyr.com HN stories on my original posts are still there, as far as I can tell. They just never hit frontpage.

Aphyr, this is very lame, it's not common to see a work like what you did, and none of your stories hit the HN front page? I don't know what to think, but I hope that at least my post will help to show more people your awesome work.

Re: Reply to Aphyr attack on Redis Sentinel

#16

Post by praptak » Mon, May 20, 2013, 4:22 PM UTC

pygy_ wrote: post #4

Tangentially related: In the PostgreSQL evaluation[0], Aphyr noticed that, if a packet confirming a transaction is dropped, the client ends up in a deadlock. Does PostgreSQL keep a record of the past transactions, and their success or failure. If so, is it possible to query it? [0] http://aphyr.com/posts/282-call-me-maybe-postgres

Yet more tangentially related: it is an instance of the Byzantine Agreement problem, which is unsolvable in general: no finite protocol guarantees consistent state in the presence of packet loss.

Re: Reply to Aphyr attack on Redis Sentinel

#17

Post by undoware » Mon, May 20, 2013, 4:22 PM UTC

aphyr wrote: post #14

undoware wrote: post #10

I'm frustrated that when the HN editors deduped the original story, they apparently deleted ALL the instances, leaving only this one. I wanted to read the discussion on the subject of Aphyr's research, not Antirez' response. It looks bad, HN. We all know that VMWare is litigious as (try looking up benchmarks sometime.) But to (presumably) cave so quickly and effortlessly suggests... well, I'm not sure. The other poss…

https://www.hnsearch.com/search#request/all&q=aphyr.com HN stories on my original posts are still there, as far as I can tell. They just never hit frontpage.

Yes, they did -- I saw them do so. There were several, in fact. And then they were gone. You've been robbed?

Re: Reply to Aphyr attack on Redis Sentinel

#18

Post by aphyr » Mon, May 20, 2013, 4:28 PM UTC

praptak wrote: post #16

pygy_ wrote: post #4

Tangentially related: In the PostgreSQL evaluation[0], Aphyr noticed that, if a packet confirming a transaction is dropped, the client ends up in a deadlock. Does PostgreSQL keep a record of the past transactions, and their success or failure. If so, is it possible to query it? [0] http://aphyr.com/posts/282-call-me-maybe-postgres

Yet more tangentially related: it is an instance of the Byzantine Agreement problem, which is unsolvable in general: no finite protocol guarantees consistent state in the presence of packet loss.

Yep, FLP applies here--but if a network works long enough to complete a round eventually, e3PC or similar can succeed. Pretty much all real-world networks do that. :)

Re: Reply to Aphyr attack on Redis Sentinel

#19

Post by lacksconfidence » Mon, May 20, 2013, 4:31 PM UTC

nutmeg wrote: post #2

A response to this article on Redis: http://aphyr.com/posts/283-call-me-maybe-redis

hmm, i'm not sure how it could be better worded, but since antirez already links to this, i had thought you were posting a response to antirez's comments

Re: Reply to Aphyr attack on Redis Sentinel

#20

Post by undoware » Mon, May 20, 2013, 4:35 PM UTC

antirez wrote: post #13

undoware wrote: post #10

I'm frustrated that when the HN editors deduped the original story, they apparently deleted ALL the instances, leaving only this one. I wanted to read the discussion on the subject of Aphyr's research, not Antirez' response. It looks bad, HN. We all know that VMWare is litigious as (try looking up benchmarks sometime.) But to (presumably) cave so quickly and effortlessly suggests... well, I'm not sure. The other poss…

Hello, 1) I no longer work for VMware, but Pivotal. Redis is open source and copyright is of the original guys that wrote the code: I, Pieter Noordhuis, other contributors. 2) I posted the link to the original article in the first very lines of my reply. Actually thanks to my reply the exposure the Aphyr research had about Redis is the greatest, compared to the other data stores mentioned. I publicly said thank you t…

Sorry, to clarify -- I was suggesting that it was possible that VMWare (a sponsor of Redis, correct?) leaned on someone. I didn't mean to besmirch you or redis, antirez, and I enjoyed your response.

It wouldn't be the first time a reputable news site was forced to bury a story by a litigious company. Sponsoring FOSS does not make any organization beyond doubt. Especially if they, say, have a history of suing anyone who benchmarks them.