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Message #15159
Re: [Branch ~dhis2-documenters/dhis2/dhis2-docbook-docs] Rev 426: Added section on using nginx as a reverse proxy to the setup documentation. Polished up the GIS s...
It is using straight HTTP, and in this example, serves up the static
content, bypassing the Tomcat server. I have not tried with the web-api,
but everything else seems to work (and is much faster than Apache with much
lower memory consumption). Would be good to know if it actually works
however. :)
Regards,
Jason
On Mon, Dec 12, 2011 at 11:12 AM, Bob Jolliffe <bobjolliffe@xxxxxxxxx>wrote:
> Hi guys
>
> I haven't used this myself, but looking at the docs it seems that
> nginx is setup to do straight http proxying ie. it is not talking ajp
> to the backend tomcat server. Is this correct?
>
> I could be wrong, but Jo/Morten this might have some implication with
> the absolute URLs being used in the web-api.
>
> Cheers
> Bob
>
> On 12 December 2011 07:15, <noreply@xxxxxxxxxxxxx> wrote:
> > ------------------------------------------------------------
> > revno: 426
> > committer: Jason P. Pickering <jason.p.pickering@xxxxxxxxx>
> > branch nick: dhis2-docbook-docs
> > timestamp: Mon 2011-12-12 09:11:53 +0200
> > message:
> > Added section on using nginx as a reverse proxy to the setup
> documentation. Polished up the GIS section a bit.
> > modified:
> > src/docbkx/en/dhis2_implementation_guide_installation_detailed.xml
> > src/docbkx/en/dhis2_user_man_creating_gis.xml
> >
> >
> > --
> > lp:~dhis2-documenters/dhis2/dhis2-docbook-docs
> > https://code.launchpad.net/~dhis2-documenters/dhis2/dhis2-docbook-docs
> >
> > Your team DHIS 2 developers is subscribed to branch
> lp:~dhis2-documenters/dhis2/dhis2-docbook-docs.
> > To unsubscribe from this branch go to
> https://code.launchpad.net/~dhis2-documenters/dhis2/dhis2-docbook-docs/+edit-subscription
> >
> > === modified file
> 'src/docbkx/en/dhis2_implementation_guide_installation_detailed.xml'
> > --- src/docbkx/en/dhis2_implementation_guide_installation_detailed.xml
> 2011-10-04 14:33:11 +0000
> > +++ src/docbkx/en/dhis2_implementation_guide_installation_detailed.xml
> 2011-12-12 07:11:53 +0000
> > @@ -532,7 +532,30 @@
> > <para>Now, just restart Apache and you should be able to view
> https://foo.mydomain.org/dhis. </para>
> > <screen>/etc/init.d/apache2 restart</screen>
> > </section>
> > - <section/>
> > + <section>
> > + <title>Reverse proxy with nginx</title>
> > + <para><ulink url="http://wiki.nginx.org";>Nginx</ulink> is a
> high-performance web server and reverse proxy with built with high
> concurrency, performance and low-memory usage in mind. For more
> installations, <application>nginx </application>may be a better alternative
> than the Apache web server for reverse proxy implementations. </para>
> > + <para>To get started, simply install nginx on your system with
> the following command.</para>
> > + <para><screen>sudo apt-get install nginx</screen></para>
> > + <para>A sample configuration file is below, and should be placed
> in <filename>/etc/nginx/sites-available</filename>.</para>
> > + <para><screen>server {
> > + listen *:80;
> > + server_name dhis.foo.org;
> > +location ~ \.(gif|jpg|png|css|js)$ {
> > +
> > +root /var/lib/tomcat6/webapps/;
> > +}
> > +
> > +location / {
> > + proxy_pass http://localhost:8080/;
> > + proxy_set_header X-Real-IP $remote_addr;
> > + proxy_set_header X-Forwarded-For
> $proxy_add_x_forwarded_for;
> > + proxy_set_header Host $http_host;
> > + }
> > +}
> > +</screen></para>
> > + <para>You will need to adjust the <varname>server_name</varname>,
> and <varname>proxy_pass</varname> variables to suit your particular setup.
> The server name must match exactly the name of the server which will be
> running DHIS. In this particular setup, nginx will serve all static content
> and then redirect dynamic requests to the application server. Once you have
> adjusted the configuration file to suit your needs, be sure to activate it
> by creating a symbolic link in the <filename>/etc/nginx/sites-enabled
> </filename>directory which points to the file.</para>
> > + </section>
> > <section>
> > <title>Performance tuning</title>
> > <para>To increase Tomcat's performance, you can install the
> native APR library by invoking:</para>
> >
> > === modified file 'src/docbkx/en/dhis2_user_man_creating_gis.xml'
> > --- src/docbkx/en/dhis2_user_man_creating_gis.xml 2011-12-01
> 07:05:24 +0000
> > +++ src/docbkx/en/dhis2_user_man_creating_gis.xml 2011-12-12
> 07:11:53 +0000
> > @@ -4,26 +4,29 @@
> > <title>Setting up GIS</title>
> > <section>
> > <title>Context</title>
> > - <para>
> > - Setting up the GIS simply means storing coordinates for the
> organisation units you want to show on the map in the database. Coordinates
> are often distributed in proprietary formats. ESRI shapefiles are the
> most common geospatial vector data format for desktop applications. You
> might find shapefiles for your country <ulink url="
> http://www.diva-gis.org/gd";>here</ulink> or many other geospatial data
> repositories on the web. Some amount of work needs to be done in order to
> use these coordinates in DHIS 2 GIS, namely transforming the data into a
> suitable format and ensuring the name which are contained in the geospatial
> data match exactly with the names of the organization units which they
> should be matched to. </para>
> > + <para>Setting up the GIS simply means storing coordinates for the
> organisation units you want to show on the map in the database. Coordinates
> are often distributed in proprietary formats and will need to be
> converted to a format which DHIS2 uses. ESRI shapefiles are the most common
> geospatial vector data format for desktop applications. You might find
> shapefiles for your country <ulink url="http://www.diva-gis.org/gd";>here</ulink>
> or in many other geospatial data repositories on the web. Some amount of
> work needs to be done in order to use these coordinates in DHIS 2 GIS,
> namely transforming the data into a suitable format and ensuring the name
> which are contained in the geospatial data match exactly with the names of
> the organization units which they should be matched to. </para>
> > <para>If you go to the organisation unit module and edit one of the
> units, you can see a text field called Coordinates. Here you may fill in
> its coordinates directly (geojson format) which is useful if you just want
> to update a couple of units.</para>
> > <para>An example point/facility coordinate:</para>
> >
> <para><programlisting><userinput>[29.341,-11.154]</userinput></programlisting></para>
> > <para>An example polygon/area coordinates string:</para>
> >
> <para><programlisting><userinput>[[[[29.343,-11.154],[28.329,-11.342],[28.481,-10.239],[29.833,-10.412]]]]</userinput></programlisting></para>
> > - <para>However, if you are going to e.g. add coordinates for all
> units at a certain level you don't want to do that manually. This is
> where the automatic GML import comes into play and the following section
> explains the preferred way of using it.<note>
> > - <para>The only projection system supported by DHIS2 is EPSG
> 4326. Coordinates must be stored with the longitude (east/west position)
> proceeding the latitude (north/south position. If you vector data is in a
> different format than EPSG 4326, you will need to reproject first before
> importing. </para>
> > - </note></para>
> > + <para>However, if you are going to e.g. add coordinates for all
> units at a certain level you don't want to do that manually. This is
> where the automatic GML import comes into play and the following section
> explains the preferred way of using it.<important>
> > + <para>The only co-ordinate reference system supported by DHIS2
> is EPSG:4326, also known as geographic longitude/latitude. Coordinates must
> be stored with the longitude (east/west position) proceeding the latitude
> (north/south position). If your vector data is in a different CRS than EPSG
> 4326, you will need to reproject the data first before importing into
> DHIS2. </para>
> > + </important></para>
> > </section>
> > <section id="gisSetup">
> > <title>Importing coordinates</title>
> > - <para>Step 1 - Simplify/generalize your shapefile</para>
> > - <para>
> > - The boundaries in shapefiles are usually very accurate. This does
> not cause any trouble for hardware accelerated desktop based GIS software,
> but it might be too heavy for the web based GIS application in DHIS 2.
> Thus, we need to make the boundary lines less detailed by removing some of
> the line points. Go to <ulink url="http://mapshaper.com/test/demo.html";>
> http://mapshaper.com/test/demo.html</ulink> and upload your shapefile.
> Then, at the center bottom you see a slider that starts at 0%. It is
> usually ok to drag it up to about 80%. In the left menu you can check
> "show original lines" to compare the result and you may want to
> give a different simplification method a try. When you are happy with the
> result, click "export" in the top right corner. Then check the
> first of the four options called "Shapefile - polygons", click
> "create" and wait for the download buttons to appear. Now,
> download the two files and overwrite the existing .shp and .shx files in
> your shapefile set (a shapefile is actually a set that has three mandatory
> files called .shp, .shx and .dbf and sometimes up to 15 files in total).
> Move on to the next step with your new simplified shapefile.
> > + <para>Step 1 - Simplify/generalize your geographical data</para>
> > + <para>The boundaries in geographical data files are usually very
> accurate, too much so for the needs of a web-based GIS. This usually does
> not affect the performance when using GIS files on a a local system, but it
> is usually necessary to optimize the geographical data for the web-based
> GIS system of DHIS2. All geographical data needs to be downloaded from the
> server and rendered in a browser, so if the data is overly complex, the
> performance of the DHIS2 GIS will be negatively impacted. This optimization
> process can be described as follows:</para>
> > + <para><simplelist>
> > + <member>Coordinates: The number of significant decimal digits
> (e.g. 23.02937874993774) should be shortened to fewer digits (e.g. 23.03).
> Although this will result in some inaccuracies on the map, given the usual
> scale at which maps in DHIS2 are produced (> 1:50,000), the loss of
> precision should not be noticeable. Normally, no more than four significant
> digits after the decimal point should be necessary.</member>
> > + <member>Polygons: In addition to shortening the number of
> significant digits, the actual number of points should also be reduced to
> an optimal level. Finding this optimal level may take a bit of
> experimentation. Decreasing the precision of the points as well as the
> number of points through generalization, will lead to degradation of the
> polygon. However, after a bit of experimentation, an optimal level of
> generalization can be found, where the accuracy of the polygon is visually
> acceptable, and the performance of the GIS is optimal. </member>
> > + </simplelist></para>
> > + <para>For polygons, we need to make the boundary lines less
> detailed by removing some of the line points. One possible method is the
> use of <ulink url="http://www.mapshaper.com/test/demo.html";>MapShaper</ulink>
> which is an online tool which can be used to generalize geographical
> data. To use MapShaper, simply upload your shapefile to the site. Then, at
> the center bottom you see a slider that starts at 0%. It is usually
> acceptable to drag it up to about 80%. In the left menu you can check
> "show original lines" to compare the result and you may want to
> give a different simplification method a try. When you are happy with the
> result, click "export" in the top right corner. Then check the
> first of the four options called "Shapefile - polygons", click
> "create" and wait for the download buttons to appear. Now,
> download the two files to your local computer (being sure to rename the
> file so that you do not overwrite your existing, original data). Move on to
> the next step with your new simplified shapefile.
> > </para>
> > <para>Step 2 - Convert the shapefile to GML</para>
> > <para>
> > - The recommended tool for geographical format conversions is
> called "ogr2ogr". This should be available for most Linux distros
> ("sudo apt-get install gdal-bin"). For Windows, go to
> http://fwtools.maptools.org/ and download "FWTools", install it
> and open up the FWTools command shell. During the format conversion we also
> want to ensure that the output has the correct coordinate projection
> (called EPSG:4326 with geographic longitude and latitude). For a more
> detailed reference of geographic coordinates, please refer to this <ulink
> url="http://www.epsg-registry.org/";>site</ulink>. If you have already
> reprojected the geographic data to the geographic latitude/longitude
> (EPSG:4326) system, there is no need to explicitly define the output
> coordinate system, assuming that <command>ogr2ogr</command> can determine
> the input spatial reference system. You can determine the spatial reference
> system by executing the following command.</para>
> > + The recommended tool for geographical format conversions is
> called "ogr2ogr". This should be available for most Linux
> distributions ("<command>sudo apt-get install
> gdal-bin"</command>). For Windows, go to <ulink url="
> http://fwtools.maptools.org/";>http://fwtools.maptools.org/ </ulink>and
> download "FWTools", install it and open up the FWTools command
> shell. During the format conversion we also want to ensure that the output
> has the correct coordinate projection (called EPSG:4326 with geographic
> longitude and latitude). For a more detailed reference of geographic
> coordinates, please refer to this <ulink url="
> http://www.epsg-registry.org/";>site</ulink>. If you have already
> reprojected the geographic data to the geographic latitude/longitude
> (EPSG:4326) system, there is no need to explicitly define the output
> coordinate system, assuming that <command>ogr2ogr</command> can determine
> the input spatial reference system. You can determine the spatial reference
> system by executing the following command.</para>
> > <para><programlisting><userinput>ogrinfo -al -so
> filename.shp</userinput></programlisting></para>
> > <para>Assuming that the projection is reported to be EPSG:27700 by
> <command>ogrinfo</command>, we can transform it to EPSG:4326 by executing
> the following command.<programlisting><userinput> ogr2ogr -s_srs EPSG:27700
> -t_srs EPSG:4326 -f GML filename.gml filename.shp
> </userinput></programlisting></para>
> > <para>If the geographic data is already in EPSG:4326, you can simply
> transform the shapefile to GML by executing the following command. </para>
> > @@ -41,11 +44,11 @@
> > Go to Services -> Import-Export, select "Preview",
> select the GML file and click "Import". Look for new/updated
> organisation units. Our intention is to add coordinates to already existing
> organisation units in the database, so we want as many updates as possible
> and 0 new. Those listed as new will be created as root units and mess up
> the organisation unit trees in DHIS 2. If any listed as new, click the
> number and the organisation units in question will appear in the list
> below. If there are any slight misspellings compared to the organisation
> unit names in the database - fix them and do the preview again. Otherwise,
> click the "discard all" button below the list and then the
> "Import all" button above the list.
> > </para>
> > <para>
> > - If the import process completes successfully, you are good to go.
> If not, check the log for hints and look for common errors such as:
> > + If the import process completes successfully, you should now be
> able to utilize the geographical data in the DHIS2 GIS. If not, check the
> log for hints and look for common errors such as:
> > </para>
> > <para>- Name duplicates in the GML file. The name column in the
> database is unique and does not accept two organisation units with the same
> name.</para>
> > <para>- The "shortname" column in the organisationunit
> table in your database has a too small varchar definition. Increase it to
> 100.</para>
> > - <para>- Special name characters in the GML file. Rename or
> remove.</para>
> > + <para>- Special name characters in the GML file. Be sure to convert
> these to appropirate XML equivalents or escape sequences.</para>
> > </section>
> > <section>
> > <title>Administering the GIS module</title>
> >
> >
> > _______________________________________________
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> >
>
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