A possible parallel to too many searches. Mea culpa. (?)

I had three separate questions involving potential problems on the board (potentially including my own actions or omissions) but each of these can wait for another thread.

Last night in a flurry of activity I subscribed to about 25 threads from BBQ and GD, with the full intention of reading all of them over the weekend. And I certainly will have the time to read them as far as I can see. Also, this morning I added 4 or 5 Cafe Society’s, but the main relevance is about 25 within half-an-hour.

(Just in case anyone is wondering, I did read several posts from those with the most compelling curiosity factor to me.)

Question: I there a problem on the board with such a flurry of individual activity? I understand that searches are forced apart in time, not because admins are mean, but because of site limitations. I did experience some really long hour-glasses after a while, when I was close to finishing up all the ones that I was interested in. So I stopped and went on to other sites.

So I was just wondering if I was tying up the board. Or was it rather more likely to be a server/internet traffic problem?

I value my membership. If I was affecting the board site, I definitely won’t be doing it again. Please advise me.

True Blue Jack

Your level of activity is not a problem. The server probably didn’t even blink at it.

The slowness of the site that you experienced is likely due to the search bug that is prevalent on a message board of this size (multi-gigabytes of data) using vBulletin.

The search method used for vBulletin has some major shortcomings that can cause the server to become unresponsive when there is a certain amount of searching, new posts, and reads going on. This is caused by:

(1) vBulletin’s search method is slow, often taking 30 seconds just for one search on the SDMB.
(2) Performing a search locks up the entire SDMB until it is finished because this is how vBulletin is designed.
(3) If someone submits a new post/thread while a search is going on, it has to wait until the search is finished (becaused the board is locked).
(4) If someone just wants to read a thread while steps (2) and (3) are occurring, they can’t because vBulletin’s coding says that a new post/thread must be finished because you can proceed to read again.
(5) Imagine there is a spike in the number of searches while it is busy at the server with new posts. People are still trying to read threads. This creates a bottleneck of steps (2), (3), and (4) even though the server has more than enough power to handle it if everything could be done at the same time.
(6) If the bottleneck increases in size faster than vBulletin can churn data, then you have a race condition where all the memory in the server can be used up. This could cause the SDMB to become unresponsive and require a reboot to get things going again.

The solution to this is to dump vBulletin’s search method and use a third party search program hosted on the SDMB, such as Sphinx .

If you want to help out right now, don’t use the search on the SDMB. Go to www.omgili.com and use that to search the SDMB.

With respect, I do not think it has ever been established that vBulletin’s search function alone is what locks the board. Most searches on here, even quite involved ones, last a matter of a couple seconds at most.

Perhaps you have information about the situation that hasn’t been made public?

Chasing Dreams, also with respect, everything in your post is complete fiction. vBulletin does not, by design, work in any of the ways you listed. There are absolutely massive messageboards that use vBulletin that don’t exhibit any of the behavior you mentioned. Can I ask what experience you have with vBulletin that lead you to believe what you’re posting?

From http://www.vbulletin.org/forum/showthread.php?t=119263 :

This is the Link that Ed Z. gave out in the previous thread about server performance issues .

I didn’t believe it at first, but read the vBulletin thread and you will see what I mean about vBulletin doing locks and how vBulletin can’t handle searches that well with a large database.

Also, your search times will vary depending on the complexity of your search. If you do boolean searches, it takes much longer than searching for one word.

Sites that don’t have these problems with vBulletin probably use one of the solutions listed in the first link above.

They’re talking about MySQL fulltext search in that thread. The SDMB doesn’t use that (or have that) option. And regarding locks in general, as I’ve mentioned I’m not a database admin, but it’s my understanding that what locking and unlocking the system does do should be instantaneous, not something we as visitors would actually be sitting around waiting for. Someone correct me if I’m wrong there.

And however it works, the anecdotal evidence remains that there are lots of very large vbulletin sites where users can search, browse, and post simultaneously to their heart’s content. In other words, what’s wrong with the SDMB isn’t a limitation or a bug with the vBulletin software.

Well, now, in fairness, I know a couple of large message boards that use vBulletin that have disabled the search function precisely because it contributes to locking-up. And example is the message board for Paradox games: which you can find here.

Every response to the OP talks about the effect of searches on the performance of the SDMB.

I don’t, however, see what search speed has to do with Jack’s question: Does a flurry of thread subscriptions have a negative impact on the board? Subscriptions do not trigger searches, so I’d say no, not at all.

That’s because it’s a strain on the server in general. If you don’t have a server that can handle it, searching can definitely cause performance issues. My only point is that vBulletin isn’t so poorly designed that it can only serve one user at a time. :wink:

Yep I’d wager you’re right. I know that I go to the User CP page way more often than every two minutes and it never holds me up.

Appears the answer to the OP is “no.” So we’re done here.