Search function bug?

[ChristianSt]

I haven't done really extensive testing on it (other then trying it on my mobile and desktop, testing both the mobile and desktop version), but for me the searched is somewhat bugged:

The first time I search something (with the normal search function, but also the advanced search) I get every time the results 1 to 25 from 500. Only after refreshing the page I get the actual number of found entries. [For example the default search for "vaarsuvius" jumps down to 82]

Mh, testing less common search terms with the default search, I encountered other odd behavior "aandarius": Showing "Results 1 to 9 of 14" Initial, down to 1-9/9 after a refresh. [I haven't found more, because honestly after trying a bunch the 30sec cooldown on the forum search just makes that troublesome ... ]


Also it seems that it is limited to 500 results. When I searched for "elan" (showing posts) it stayed 500 after a refresh. But if I go to further pages that number drops. At Page 7 of the results I'm at "Results 151 to 175 of 497", Page 19 is "Results 451 to 475 of 490". Which even does seem random. I made the search "elan" again (both time for posts), and it ended with Page 18 "Results 426 to 444 of 444" ... The third time it ended again @490, though I'm not aware I have changed anything in other search parameters - the fourth try ended at Page 16 with 399 results. Even if I did somehow manage to screw up search parameters this whole "jumping maximum results" is more than strange alone

I haven't noticed other problems with the search, but this behavior seems extremely odd to me, so I wanted to point it out (or at least see whether I'm the only one with that problem).

[Divayth Fyr]

or at least see whether I'm the only one with that problem.

Definately got - I get the same bug. In most cases it starts by showing that there are 500 results, but when I searched for "Telvanni" I got 111 results which dropped to the real value of 42.

[Rawhide]

Results are currently limited to the first 500, so you won't see more than that.

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It may take a bit to diagnose the specific cause, so please play around with searching and document it completely.

e.g. How you searched (from the quick bar or which tab of the advanced search), all search options you used, what number of results you got, how many pages it displayed, in what way all of these things changed as you clicked on things (and what you clicked on).


Please also take screenshots (but link them rather than embed) of each step and the results.

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Also, please note where searching actually works correctly, if it works correctly.

[ChristianSt]

"currently limited to the first 500"? Will that restriction be changed in the future? Because arbitrary limiting search results doesn't sound that great. (And I have the feeling it might be related to this bug)

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To make it extra clear, I use the following words meaning the following stuff:

Word	Action
(go) back	Using the "Go back one page"-feature of my browser, using the arrow in the top left corner.
(page) refresh	Refreshing the page by hitting F5
jump to page X	Using the insert go to page feature of the drop-down menu that gets displayed hitting the bottom "Page Y of Z" button, entering X and hitting return.

Using the (presumable) default search (typing something in the top right corner and hitting enter), I get the following:

• "aandarius", default search: Initially 1-10 from 15; after a Page Refresh (F5) 1-10 from 10. This seems to reproducible to me. [Also before making this thread it was at 1-9 from 14, so the search has correctly included this thread]
  
  
• "elan", default search: This one was strange:
  1. First, up to 500
  2. I'm not exactly sure whether I did a Page Refresh before doing so, but from the results I tried first to jump to page 20 (no result), going back in my browser and it showed me up to 250 results.
  3. So I jumped to page 10 resulting in the same error, after a refresh it was at up to 225 results.
  4. Next I settled for page 7 showing me the (presumable) correct end of 151 to 157 of 225. I tried to jump (or maybe only hitting the page 8/next page button) to page 8 giving me no results.
  5. After some time I did refresh that again (my browser said "To display this page, Firefox must send information that will repeat any action (such as a search or order confirmation) that was performed earlier.", probable because to resend the "jump to page 7 command"), and got first to 151 to 157 of 169 and after another refresh it settled for 151 to 157 of 157 (I did this for the second repeat, if you look at the seachid and wonder why they differ).
  6. I did repeat that (maybe some slightly different jumps/refreshes) with a different intermediate number (Screens 1 2 3 4 5), and did another try with directly jumping to page 7, giving me slightly different intermediate numbers, too (Screens 1 2 3). Though the end result was the same.
  
  
• "elan", advanced searched for single content showing posts - now it gets really strange. I tried this 3 times with 3 different results:
  
  1. First try: Basically a standard search for single posts (settings.p1, settings.p2):
     1. I refreshed it and it stayed at 500.
     2. I jumped to page (I think) 20 (maybe 15) getting no result.
     3. Back and refreshed to 496.
     4. Jumping to page 10 succeeded, 496.
     5. Jump to 15 no result.
     6. Back and refreshed to 350.
     7. Jumping to page 13 succeeded, 350.
     8. Jumping to page 14 succeeded, final 347.
  2. Second try, same settings:
     1. Directly jumped to 14, no result.
     2. Back and refreshed to 496.
     3. Jumping to page 12 succeeded, 496.
     4. Refreshed to 323.
     5. Jumping to page 13 succeeded, final 323.
  3. Third try, same settings:
     1. Refreshed to 500.
     2. Jumping to page 10 succeeded, 500.
     3. Refreshed to 495.
     4. Jumping to page 15 succeeded, 495.
     5. Refreshed to 388.
     6. Jumping (maybe I used the 16 or next page button, I'm not 100% sure on it) to page 16 succeeded, final 388.

Interestingly, all 3 elan-post-searches ended in different posts (though I only checked the one included in the screenshot). I would assume that somehow the SQL query discards some inital results (which isn't really the first 500 but any 500 hundred - or maybe the top 500 hundred results of a query, which isn't ordered, thus non-determenistic). Though how/why that happens I can only speculate (not that the SQL-assumption was anything else than speculation )

I linked to the screenshots in the text. If you want to see them all along you can go directly to the photobucket folder where I uploaded them.

Maybe I will do some more, but since it is rather boring work to document and upload all the stuff (and I honestly think that is more than enough for an initial bug report), I wouldn't count on that. (Unless you point me to specific things I should test).

I can't really say if any part of the search function works 100% correct, though I had the feeling it works beside the result number thing. (I succeeded in hunting down some old posts of mine to enable my signature. Though I haven't double-checked whether it found all.) But after seeing the "elan-post" search behavior, I'm not sure whether some results get dropped or not. But since the "elan-default (presumable thread)" search seemed to produce the same results, maybe non-deterministic behavior only starts after a certain threshold of results.

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IIRC I had similar results while searching for posts from users (though I didn't paid much attention to it), but right now I'm not in the mood to do more testing.

[Rawhide]

"currently limited to the first 500"? Will that restriction be changed in the future? Because arbitrary limiting search results doesn't sound that great. (And I have the feeling it might be related to this bug)

500 is the default and what we had previously prior to search being disabled. It's in place to prevent searches for commonly used terms killing a server.

[Weirdlet]

My current search bug is that if I try to search, it tells me I don't have permission to do so.

[Rawhide]

My current search bug is that if I try to search, it tells me I don't have permission to do so.

Searching is currently disabled.

[Weirdlet]

That'd do it.

[Rawhide]

ChristianSt: Thank you for that. We had actually already identified that there was an issue (or two), and I was in the process of writing up a very detailed bug report. We first noticed it while looking for threads to add prefixes to, shortly before going live. I have added your diagnostic searches to the bug report (actually, I linked directly to this thread to provide additional information beyond what I included in the report).

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I have found a workaround for one of the issues. When performing an Advanced Search with the Single Search Content Type and Show Results as: set to Posts, do not use the Jump to page: function. If you manually click on each page number after searching for, say, "elan", you can make it all the way to Page 20, and it will provide you with Results 476 to 500 of 500.

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P.S. Also, searching has been re-enabled.

[ChristianSt]

I'm glad when my bug report is helpful

But I find it rather strange that the "jump to page X"-feature has a problem.
I think with that information I might mess around a bit more later today.
(Some bugs are really weird...)

[ChristianSt]

All of the following is done with the same "elan search for post"-search. I didn't bother to take a bazillion meaningless screenshots [ok, maybe it can be relevant which posts are shown in the final result - but with taking screenshots it would have taken way too much time to do the following tests right now]. The only information that seemed useful was the X to Y of Z result numbers. So that (and the searchid, because if the searches got stored on your side, that might be helpful, too) is the only information I wrote down.

I have found a workaround for one of the issues. When performing an Advanced Search with the Single Search Content Type and Show Results as: set to Posts, do not use the Jump to page: function. If you manually click on each page number after searching for, say, "elan", you can make it all the way to Page 20, and it will provide you with Results 476 to 500 of 500.

I couldn't reproduce this to arrive at 476 to 500 of 500 on page 20. I tried several times to go from page to page and arrived at 490, with the following steps:

page	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
max results (of X)	500	500	500	498	498	497	497	496	496	494	494	494	494	493	492	492	490	490	490	490

After arriving at page 20 with 476 to 490 of 490, I jumped some times (20 -> 10 -> 20 -> 1 -> 20), still getting the same result.

I did this 5 times, getting the same results:

• 3 times using the right arrow button for next page [serachids: 5562, 5568 and 5570]
• 1 time using the page X number button to go to the next page [searchid: 5573]
• 1 time using the jump to page X dropdown menu [searchid: 5580]

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Next I tried to jump to the max page each time, yielding the following result:

jumped to page X	20	20	19	19	18	18	17	17	16	16	15	15	14	14
max results (of X) after going back and refreshing the page	498	475	475	450	449	425	424	400	400	375	375	350	350	325

After that a jump to page 13 succeeded, resulting in 301 to 314 of 314.
I tried this twice [searchid 5601 and 5608]

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With searchid 5613 I tried multiple things.
Thirst I tried multiple refreshes, but even after 10 refreshes it staid by 500 results.
Then I jumped to page 20 numerous times, but even after 5 tries it didn't dropped below 475.
I then jumped to page 13, going to 301 to 314 of 475. The maximum number decresead first to 471 and then 314 with refreshing the page (requiring resending information).

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For the final test [searchid 5622] I jumped directly to 13, resulting in 301 to 314 of 500. The maximum number decresead first to 494 and then 314 with refreshing the page (requiring resending information).


That's it for now. As it seems the transition between pages makes some really weird stuff.

[Zherog]

I'm glad when my bug report is helpful

I wish even half my user base at my day job provided that much information in bug reports. I can't tell you how much time I spend finding out what the bug is before I even start trying to see what or why. Kudos, good sir!

[ChristianSt]

I wish even half my user base at my day job provided that much information in bug reports. I can't tell you how much time I spend finding out what the bug is before I even start trying to see what or why. Kudos, good sir!

I think that is mostly because I'm studying Computer Science myself, and while I honestly don't have that much practical experience, I did my fare share of coding and know that locating the bug is way more troublesome most of the time than actually fixing it .

[Rawhide]

I wish even half my user base at my day job provided that much information in bug reports. I can't tell you how much time I spend finding out what the bug is before I even start trying to see what or why. Kudos, good sir!

You should have seen my bug report. It was even more detailed.

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So, apparently this is just how searching works now. The search will pull up the results as they are in the index, and as you work your way through the pages, it will eliminate erroneous entries.

I've seen a similar thing on Google, with the number of total results decreasing on each page turn.

[ChristianSt]

So, apparently this is just how searching works now. The search will pull up the results as they are in the index, and as you work your way through the pages, it will eliminate erroneous entries.

So it is not possible to fix this?

Honestly the reduced results (getting only to 490 instead of 500) is annoying, but not that problematic. (I assume it could be be the case that some posts are inaccessible to me, but not to you, and it is cut down to 500 before access rights are controlled, missing some entries later.)


But was really bugs me is the "Jump to Page X": It doesn't appear to merely filter out some wrong posts but to drop whole pages of results. After trying to jump to the currently displayed maximum page for quite some time (with steadily requiring to lower that number), I was honestly surprised to see it stop at page 13. [I kinda assumed it would reduce the results until I was at page with 25 results to display.]

I haven't tested what intermediate jumps do (so say to page 5 7 or 10; though from my first testing it seems to be not much better), but right now either two things are imo possible:

• The "go only from one page to the next page"-solution shows erroneous entries. (because it shows 490)
• The "jump to page X"-button drops valid results. (because it shows 314)
• Maybe even both. (though I think that only the drops valid results apply)

All of this would be really bad behavior for a search function. Yes between this and "no search at all" this is way better, so if the only solution would be to shut down the search again for indefinite time, then I think we should live with it.

But right now I think the Jump to Page X feature causes some serious troubles (and probably should not be used if you want to see more results). If that is the case, I think it would be good to stick a warning somewhere that this feature doesn't work that well (if it is possible).

[Zherog]

You should have seen my bug report. It was even more detailed.

I can only dream. Twice yesterday - from the same analyst, even - I got, "it doesn't work" as the report. At least upon asking, she had decent info about the first one ("I expected to see X, Y, and Z on the report but they aren't showing up; A did show up as expected."). The second one, though, was a comedy tragedy of errors about lack of information, even after asking several times.

So it is not possible to fix this?

Honestly the reduced results (getting only to 490 instead of 500) is annoying, but not that problematic. (I assume it could be be the case that some posts are inaccessible to me, but not to you, and it is cut down to 500 before access rights are controlled, missing some entries later.)

I'm not super-familiar with vB's table structure, but as I recall when you do a search it doesn't actually look at the thread or post tables. Instead, your search runs against a special table that indexes each word of each post. That index of words is massive, but it allows the database to process the request much faster than if it looked through the actual text fields.

Your guess here is a real good reason as to why there might be false hits. The goal of the first reply from search is likely to give the user something as quick as possible, and so it likely grabs details for the first 20 (or 50 or whatever) and then uses the results from the index for the remainder. If so, it'd make sense to then have some of those results drop away because of forum permissions. Depending on how the index is built (and maintained by the software) you could also potentially get false hits from deleted posts, edited posts, or just the index "confusing" two terms that maybe are similar but not quite the match you need.

That doesn't exclude or excuse any actual errors, of course. Just some commentary on the behind the scenes. When I first heard how it was done, I thought it was insane; but the more I see it in practice - phpbb does the same basic thing - the more I realize it was a pretty elegant solution to searching what amounts to massive amounts of data that are stored in (more or less) binary fields. (The databases use special data types for posts. The actual type varies from database to database, but they all use the concept of a clob object. Generally speaking, clob data types are efficient to store and manipulate but are bad (or in some cases impossible) to search.)