[OSM-dev] Effort in the US wasted until TIGER import is complete?

Nathan Rover NRover at websitemakers.com
Wed Mar 28 07:52:27 BST 2007


Don,
Good to see that your on-board with the TIGER database first approach. I 
really think this will be the best way to go about the import. I too 
would like to do this right even if it takes a little longer.

I'm curious if Thomas has any thoughts on this course of action, or 
anyone else who is interested in the TIGER import.

Yes, I'm downloading the march 07 data.

Yeah, import scripts will be the first step. Thomas and I had talked 
about using Python, will this be alright for you? It should not take too 
long to make import scripts. I might also write a script to unzip, and 
build a directory structure for all the TIGER text files. It would take 
along time to unzip them by hand.

The server I'm going to use is an IBM x330, it has dual PIII 1.16 Ghz 
CPUs, dual SCSI U160 36GB drives, and at least 1 GB of ram I could put 
in like 4GB (borrowed from other dev servers) for a few days while 
running the import files. Not the fastest server, but they are very 
reliable, and it won't be doing anything else, so all the resources can 
be devoted to the import. They are also capable at running at a vary 
high sustained load without any thermal issues. I'm going to be running 
this out of my office, so it will only have a DSL connection. I most 
likely will not be driving (6 hr each way) to my hosting facility any 
time soon, if I do, I will put it up on the T1 line. If you feel so 
inclined we could make a cluster.... I have 5 available dev servers 
right now. but I have a feeling it would take longer to set-up the 
cluster then it would to just run the scripts on the one server. ;-)

I think we should also address the issue of "Effort in the US wasted 
until TIGER import is complete?" that way we could eventually change the 
subject line to something like "TIGER import."

My first thought is effort is not necessarily wasted, but you might as 
well wait and see what your area looks like once the data is imported. 
And because of the way we are going to import the data, i.e. on a dev 
machine first, we wont have to worry about writing over roads that 
currently exist in the OSM database. When it comes time to make the 
merger we can then compare side by side current roads to the TIGER 
version of the road. we should be able to set up some guidelines to 
determine which version of the road is better, then make the necessary 
changes. I think one thing we should work out soon is a Key/Value pair 
for identifying whether the way or node is from a user, or TIGER, and 
also which version of TIGER. In a year, we will most likely have an 
updated version of the TIGER files to import, so, we will need a way to 
first figure out what changes were made between the two versions, this 
could probably be done with the mySQL TIGER database, then from there 
make a set of new roads and roads that need to be updated. then this 
information will need to be sent to the server and if the existing data 
is marked TIGER then it can be automatically updated, if it was last 
updated by a person then the two roads will need to be analyzed by a 
person to determine which would be the most accurate. I think this TIGER 
data is going to be an important part of the US OSM effort. It would 
take such a long time to map and update the roads in the US that unless 
there were a few thousand volunteers all over the country, there is no 
way the US would ever get mapped without the TIGER data. but even with 
the tiger data I think volunteers will still play an important part. I 
know after the import is done one thing that I'm looking forward to 
doing is mapping the foot paths of my local state parks. Some of the 
more complex interstate ramps and interchanges might also need to be 
mapped by volunteers. I'm not sure how well the TIGER data handles exit 
and entrance ramps.

I would also like to hear from the OSM database admins regarding whether 
or not after we're done and the data is tested we would be able to make 
a copy of the database with all the TIGER Data then ship it over on DVD, 
and have it imported some night. I will also need a Empty version of the 
current database to put on the dev computer. and were going to have to 
figure out how to handle the keys between the two versions of the 
databases.

Thanks, Nathan Rover

Don Smith wrote:
> I agree with the idea of putting it in sql first. I think it would 
> produce more reasonable data as you're correct that dealing with 
> interstates, or even state routes across multiple counties would be a 
> problem. My only concern is that using a database is always slower 
> than file io and memory, especially with large record counts. However 
> fast and wrong is worse than slow and right.
>
> Did you get the latest release of the data (March 3?).
>
> I assume you would need something to load the data, looking at the 
> tiger data dictionary this does not seem to bad as each column has a 
> fixed width, and strings could be trimmed. Is the machine you have in 
> mind for the testing environment somewhat substantial? Also no 
> objections to debian.
>
> Don Smith
> On Mar 28, 2007, at 12:26 AM, Nathan Rover wrote:
>
>> Don,
>> yeah, idea expressed in last e-mail would also solve this problem.
>>
>> Nathan
>>
>> Don Smith wrote:
>>> Tiger contains roads, railroads, various other transportation 
>>> features, landmarks (such as churches, schools, parks, and cemeteries).
>>> More info here:
>>> http://www.census.gov/geo/www/tiger/tiger2006se/tgr2006se.html
>>>
>>> I didn't see the importer dealing with the other data, but I haven't 
>>> checked too closely. A new tiger file was released at the beginning 
>>> of the month, which claimed to correct some of the data, though in 
>>> the second half of the year they're moving to shapefiles from their 
>>> own proprietary text format.
>>>
>>> Don Smith
>>> On Mar 27, 2007, at 11:16 PM, Cory Lueninghoener wrote:
>>>
>>>> As someone who has done a fair amount of US mapping over the last
>>>> couple of months (see the Chicago area), I'm curious: what exactly
>>>> does the TIGER database hold?  Is it just street "segments" with names
>>>> and endpoints?  Does it have interstates, house number information,
>>>> any other street information (size, direction, etc.) or anything else
>>>> of use?  I definitely look forward to having at least a base for the
>>>> whole country done within a matter of weeks (months), but assuming
>>>> we'll still need to tag lots of information and add things like train
>>>> lines, interstates (?), parks, etc. I'll keep up my manual efforts
>>>> with plans to port them over when the time comes.
>>>>
>>>> On 3/27/07, Don Smith <dcsmith at gmail.com> wrote:
>>>>> Is there a test machine setup?
>>>>> I'm still looking at the code. For simplicity's sake, I'd like to
>>>>> remove the ability to daemonize the code, and just run it from the
>>>>> command line as a regular process, with a high priority. If the idea
>>>>> is to do this on a testing db instead of the main db, and then import
>>>>> a dump of the db then I believe this makes sense. Another thing,
>>>>> someone was talking about setting up a copy of osm to import into.
>>>>> Instead I'd like to suggest that this data is just loaded into a
>>>>> blank template until everything works, then worry about merging the
>>>>> us data, either through using something like a temp tag to
>>>>> differentiate it and merging manually, or by doing something
>>>>> programatic after the fact. Whatever the user contributions are I
>>>>> would assume they're much smaller, although probably more accurate
>>>>> than tiger data.
>>>>>
>>>>> Don Smith
>>>>> On Mar 23, 2007, at 1:29 AM, Nathan Rover wrote:
>>>>>
>>>>> > I'm thinking we need to set up a server with a mirror of the 
>>>>> current
>>>>> > database, then just run a few counties then eventually a large 
>>>>> batch
>>>>> > (one state at a time?). Then we can conduct some rigorous testing
>>>>> > and if
>>>>> > the data looks good and we won't cause too much of problem on the
>>>>> > production server, we could then ship the data across the pond 
>>>>> (ether
>>>>> > over the net or fedex some DVDs). Then one night perhaps an admin
>>>>> > could
>>>>> > import the data. I've never been a big fan of messing with 
>>>>> production
>>>>> > servers, and it seems to costly both in time and bandwidth to 
>>>>> try and
>>>>> > run exports from TIGER data on a box in central Missouri, to the
>>>>> > UK, at
>>>>> > one or three second intervals. especially when this will 
>>>>> requirer lots
>>>>> > of testing to make it work correctly.
>>>>> >
>>>>> > I have the hardware for the mirror, and I'm working on getting the
>>>>> > TIGER
>>>>> > data. If this is a direction everyone agrees with then the next
>>>>> > thing I
>>>>> > need is a little guidance on how to set up a server that will be a
>>>>> > good
>>>>> > software mirror to the production one. The closer the software 
>>>>> setup
>>>>> > matches the production machine (especially the database system 
>>>>> and the
>>>>> > APIs ) the better our testing can be and the less likely there will
>>>>> > be a
>>>>> > problem down the road when we try and integrate the data onto 
>>>>> one box.
>>>>> >
>>>>> > Can someone send me a copy of the ruby code?
>>>>> >
>>>>> > Nathan Rover
>>>>> >
>>>>> > Don Smith wrote:
>>>>> >> No, I'm currently not familliar with the data model so I should 
>>>>> look
>>>>> >> into that.
>>>>> >> As for a 1 sec/insert cycle, if we don't do it on the primary 
>>>>> db, it
>>>>> >> makes no immediate sense, and I'd be interested in  timings 
>>>>> without
>>>>> >> it. I have no idea how many inserts are going on but, I would 
>>>>> guess
>>>>> >> from a ballpark on the size of tiger that you'd be right.
>>>>> >> Again I'll look at the ruby code tonight, and if someone has a 
>>>>> schema
>>>>> >> for osm that'd be nice. If whoever did the original script could
>>>>> >> outline their thinking that would be helpful as well.
>>>>> >> I am subscribed to the dev list.
>>>>> >> On Mar 23, 2007, at 12:06 AM, Thomas Lunde wrote:
>>>>> >>
>>>>> >>
>>>>> >>> On 3/22/07, Don Smith <dcsmith at gmail.com> wrote:
>>>>> >>>
>>>>> >>>> Thomas,
>>>>> >>>> do you have a machine setup? I'll look at the code tonight, 
>>>>> but you
>>>>> >>>> seem to have a better grasp of the operations going on. Any
>>>>> >>>> ideas in
>>>>> >>>> what specifically needs to be done?
>>>>> >>>>
>>>>> >>>> Right now, the two tasks appear to be aggregation of related
>>>>> >>>> segments
>>>>> >>>> into ways (?) and the 1 sec insert cycle. I would suggest
>>>>> >>>> instead, if
>>>>> >>>> possible that we load the data into mysql, and then when it's
>>>>> >>>> ready,
>>>>> >>>> batch import the sql into the master db(does this make sense?
>>>>> >>>> Instead
>>>>> >>>> of running the script twice, run it once, dump the db, and then
>>>>> >>>> import the dump?).
>>>>> >>>>
>>>>> >>> Don -
>>>>> >>>
>>>>> >>> I do have a server that could be used, but it sounds like Nathan
>>>>> >>> has a
>>>>> >>> better one.  He is/has downloading/downloaded the latest TIGER 
>>>>> data.
>>>>> >>> Both of us need to have a better understanding of the OSM current
>>>>> >>> data
>>>>> >>> model than at present.  Pointers at particular documentation
>>>>> >>> would be
>>>>> >>> helpful, otherwise I'll just look around the site and the code.
>>>>> >>>
>>>>> >>> What I think I understand is that the 1 sec insert cycle of 
>>>>> the old
>>>>> >>> Ruby code would still take weeks/months to do an import.  Is that
>>>>> >>> right?
>>>>> >>>
>>>>> >>> If so, it seems that there's got to be a better way. I agree with
>>>>> >>> you
>>>>> >>> that using seperate servers to do a higher speed import and 
>>>>> then to
>>>>> >>> dump the data from DB to DB directly would seem to be the smarter
>>>>> >>> approach.
>>>>> >>>
>>>>> >>> Are you already familiar with the OSM data model and/or with 
>>>>> the old
>>>>> >>> Ruby import code?
>>>>> >>>
>>>>> >>> thomas
>>>>> >>>
>>>>> >>>
>>>>> >>>
>>>>> >>> Nathan,Don -- if y'all are subscribed to the Dev list, let me
>>>>> >>> know and
>>>>> >>> I shan't cc: you directly.
>>>>> >>>
>>>>> >>
>>>>> >>
>>>>> >> _______________________________________________
>>>>> >> dev mailing list
>>>>> >> dev at openstreetmap.org
>>>>> >> http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/dev
>>>>> >>
>>>>> >>
>>>>> >>
>>>>> >
>>>>> >
>>>>> >
>>>>> >
>>>>> > _______________________________________________
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>>>>>
>>>>>
>>>>> _______________________________________________
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>>>>>
>>>>
>>>>
>>>> --Cory Lueninghoener
>>>> Perl, C, & Linux Hacker
>>>> http://www.wirelesscouch.net/~cluening/
>>>
>>>
>>>
>>
>>
>>
>
>
>







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