Seeking Alpha

H. T. Love's  Instablog

H. T. Love
Send Message
Spent over 30 years in computer systems work, many different functions. Owned my own business for awhile. Got tired of it (managing employees is not my baliwick) and stopped doing it professionally. Did other things, off and on, for some more years and finally bumped into this investing/trading... More
  • Loss of Data on SA: Mechanical or Procedural Error Seems Likely. 6 comments
    Dec 13, 2009 6:50 PM
    I recently confirmed to myself that comments were be "lost" from articles in SA. The comments still exist (the ones I could see) under the SA user comments section and point to the articles or instablogs correctly. When you click the "view article" link and then search for the comment in the article or instablog it may not be found.

    I did my usual "brain dump" communique to SA to make them aware.

    I'll update this and the link in the chat to it as things warrant.

    HardToLove

    ==========================================================
    Sent To SA on 12/10

    Hi Koby and Boaz,

    While reviewing some of the older posts of folks I've begun following, I encountered comments attached to the SA user that did not appear in the article when I clicked through to view the article.

    This is probably *very* widespread, as there are many possible causes and I saw it on quite a few pages on this one user.

    For confirmation of the problem, go to user Doubleguns and go to the last page of his comments. Select a comment or few and click through to view the article. Then use your browser's search facility to find all occurrences of Doubleguns. There will be several instances where the comment you linked *from* does not appear in the article.

    Boaz will be glad to know that this could cause some folks to believe that comments were intentionally deleted because the user did not go back in their comment stream and note the comment was still attached to their user ID and correctly deduce that a mechanical problem was the cause (apparently).

    Anyway, potential causes are manifold: hardware crash without adequate RAID facilities to assure "lossless crash and recovery", coding errors, incorrect restore and reconstruction of data from backups, (possible) incorrect use of SA editing facilities with SA, ...

    NOTE: the following is the natural output of an "old hand" that sounds like I'm trying to tell you how to do your job. Being as everyone in the world is younger, and maybe less experienced, this is unavoidable. I always operate in "brain dump" mode.

    I offer my apologies in advance for any angst you may experience at this presumptuous action.

    Assuming you run some RDBM system (or even a hierarchical one, but few do these days), you need to run an SQL query that makes a sorted list of all comments with the user as root and a matching one with the article as root. Your programmer will know the needed sort hierarchy, Then a mechanical match of comments found in the two should produce a difference list which can be formatted for input to a mechanical update to the RDBM. Of course, I'm thinking in *IX terms and have no idea if these facilities are easily available on whatever platform you use.

    An inspection of code may be warranted along with "boundary condition" tests to locate/eliminate code as a potential culprit.

    In my opinion, your hardware platform should include a hardware raid controller (real hardware, not "fake raid" such as provided by many embedded controllers and accessible via BIOS setup) with on-board cache and battery backup to allow complete flushing of cache prior to actual spin-down.

    A journaling file system would also provide a lot of additional robustness.

    I will not address other potential processes, such as periodic "live snapshot" and backup since I've no idea if your configurations can support this facility.

    Regardless, I would suggest that any reload/reconstruct processes that are used should be followed by thorough consistency checks as errors detected immediately are usually much easier to correct than those which have "aged gracefully in obscurity".

    If you have any comments or questions, I'll be happy to converse further with you.

    =========================================================

    Sent 12/11 a little later

    I almost forgot: the mechanical rebuild may be just a simple rebuild of index(es), depending on your specific RDBM system and they way you have the relations structured and maintained.

    =========================================================

    12/11 Boaz responded that since it was technical, he'd let Koby handle it.

    =========================================================

    Sent 12/14

    Koby,

    In my prior post I forgot to mention possible race conditions and transaction commit failures as possible causes for the data losses.

    Also, I've done an instablog, because a couple of folks asked to be kept informed, here

    A comment there seems to confirm that a mechanical problem exists.

    If more convenient for you than e-mail, I'll keep an eye on it and you can comment there as you desire and I'll respond as appropriate.

    =========================================================

    12/16 sent this to support@seegingalpha.com

    I posted some potential issues directly to Koby and Boaz 12/10-12/14. Usually I hear something back fairly quickly.

    Any word? Confirmed problem? Investigating?


    Themes: SA support
Back To H. T. Love's Instablog HomePage »

Instablogs are blogs which are instantly set up and networked within the Seeking Alpha community. Instablog posts are not selected, edited or screened by Seeking Alpha editors, in contrast to contributors' articles.

Comments (6)
Track new comments
  • John Lounsbury
    , contributor
    Comments (3978) | Send Message
     
    HTL - - -

     

    That may explain why I had to confess a couple of times to people in comment streams that I couldn't find what they were referring to to when I wanted to discuss something that followed from the missing reference. I was concerned that I might be missing a key aspect of their point by not seeing the reference.

     

    I never thought to do the research that you have done.
    13 Dec 2009, 11:58 PM Reply Like
  • John Lounsbury
    , contributor
    Comments (3978) | Send Message
     
    HTL - - -

     

    I just looked at an Andrew Butter article on gold. The first three comments he replied to are missing.
    14 Dec 2009, 12:03 AM Reply Like
  • Michael Clark
    , contributor
    Comments (8743) | Send Message
     
    Good work, HTL.
    14 Dec 2009, 01:10 AM Reply Like
  • H. T. Love
    , contributor
    Comments (17877) | Send Message
     
    Author’s reply » John and Michael,

     

    I don't want to take credit where it's not due. I was only "researching" by reviewing comments and articles, not looking for the problem.

     

    Once I noticed the problem, it still wasn't research. I just drew on my background and thought I should share with SA and others since there has been some concern that comments were being intentionally deleted for nefarious reasons.

     

    With some of this suspicion directed at SA, possibly unjustly, it was only natural for me to make known what I found and my thoughts on it.

     

    HardToLove

     

    On Dec 13 11:58 PM John Lounsbury wrote:

     

    > HTL - - -
    >
    > That may explain why I had to confess a couple of times to people
    > in comment streams that I couldn't find what they were referring
    > to to when I wanted to discuss something that followed from the missing
    > reference. I was concerned that I might be missing a key aspect
    > of their point by not seeing the reference.
    >
    > I never thought to do the research that you have done.
    14 Dec 2009, 06:34 AM Reply Like
  • Koby Menachemi
    , contributor
    Comments (16) | Send Message
     
    Hi HTL,

     

    As I wrote you in the email we are working very hard on a very cool release going out soon so I have less time for emails (as well for sleep and even say hi to my wife ;-)

     

    First, re "I offer my apologies in advance for any angst you may experience at this presumptuous action. " -- no worries. We ALWAYS welcome new ideas and any feedback we can get from our valuable users!

     

    Re the issue you've raised: we checked this and there isn't any malfunction in the system. I believe the cause is that in our latest release we've tried to split the comments into group of 20 with pagination and when linking back to the article page, the specific comment wasn't always on the first page (but you could see it if you continue browsing the other pages). The way our system works does not allow showing comments on user profiles without having them at the article page itself (i.e., they are fully synced in real-time). Even if specific comment being deleted (spam, etc.) it will not show at the user profile.

     

    Together with that I bring some good news on that issue: as we found out the latest change wasn't so successful we are going to improve it in the upcoming release (and this is the least exciting part of the release ;-) so you will see the first 20 comments at the article page but then you can switch to a single page with all the comments stream. This was based on valuable feedback from our users - we are not perfect but we do try to improve ourselves...

     

    I'll be happy to hear any thoughts you and others have about this issue.

     

    K.
    16 Dec 2009, 07:02 PM Reply Like
  • H. T. Love
    , contributor
    Comments (17877) | Send Message
     
    Author’s reply » On Dec 16 07:02 PM Koby Menachemi, CTO Seeking Alpha wrote:

     

    > Hi HTL,
    ><snip>

     

    > Re the issue you've raised: we checked this and there isn't any malfunction
    > in the system. I believe the cause is that in our latest release
    > we've tried to split the comments into group of 20 with pagination
    > and when linking back to the article page, the specific comment wasn't
    > always on the first page (but you could see it if you continue browsing
    > the other pages).

     

    I'm sitting here with egg on my face. I /never/ noticed the "new" feature that paginated the comments within the articles or instablogs, even on articles in which I was manually scrolling and reading all the comments. What's "EGGsaperating" is that I am usually pretty good noticing things, especially when looking for "issues". I guess when I'm looking for certain things, like a specific commenter, I get "tunnel vision".

     

    It seems that in potential causes I forgot to list "User inability to notice and use the system features". :-((

     

    In this case, using the browser's search-previous feature (to go from bottom towards top in the page) would position me in the page such that the next/previous page bar didn't show. Another search for the previous would then again position in the page such that the next/previous page bar wasn't visible. But there were /many/ cases where I manually scrolled and /still/ I did not notice it, so I have no excuse

     

    I have garnered another "Aw Shit". :-((

     

    Let me stick it here in my bucket with the many others from years past.

     

    Oh well. When I look stupid I do it right.!

     

    > The way our system works does not allow showing
    > comments on user profiles without having them at the article page
    > itself (i.e., they are fully synced in real-time). Even if specific
    > comment being deleted (spam, etc.) it will not show at the user profile.
    >
    >
    > Together with that I bring some good news on that issue: as we found
    > out the latest change wasn't so successful we are going to improve
    > it in the upcoming release (and this is the least exciting part of
    > the release ;-) so you will see the first 20 comments at the article
    > page but then you can switch to a single page with all the comments
    > stream.

     

    I like that. When I'm searching for something, that will be more convenient. I hope you make it really, really, really, really noticeable for folks like me. That is, it needs to hit me with a "clue bat" so that I don't overlook it like I did that other little feature. :-))

     

    > This was based on valuable feedback from our users - we are
    > not perfect but we do try to improve ourselves...
    >
    > I'll be happy to hear any thoughts you and others have about this
    > issue.
    >
    > K.

     

    I apologize to you and all the other folks for wasting your time on this. I'll try to be more astute in the future.

     

    HardToLove
    17 Dec 2009, 07:08 AM Reply Like
Full index of posts »
Latest Followers

StockTalks

More »

Latest Comments


Instablogs are Seeking Alpha's free blogging platform customized for finance, with instant set up and exposure to millions of readers interested in the financial markets. Publish your own instablog in minutes.