May 4-May 31 was the bonding period for my GSoC. I utilized this time to learn more about the codebase and started digging deeper into the specifics of the project requirements. I was provided a server (sponsored by OpenCage) to set up the Nominatim planet database. It was my first time working with such massive data. My mentors, Sarah Hoffmann and Marc Tobias helped me in setting up the server.

Installation and server setup:

The following is a brief of the steps I followed.

1. Created nominatim user without login permission

   sudo useradd -d /srv/nominatim -s /bin/false -m nominatim

2. Postgres configuration changes:

    shared_buffers = 2GB
    maintenance_work_mem = 10GB
    autovacuum_work_mem = 2GB
    work_mem = 150MB
    effective_cache_size = 24GB
    synchronous_commit = off
    max_wal_size = 1GB
    checkpoint_timeout = 10min
    checkpoint_completion_target = 0.9
    effective_io_concurrency = 500
    random_page_cost = 1.5
   
    # reenabled these two after initial import 
    fsync = off
    full_page_writes = off
   

   sudo systemctl restart postgresql

3. The data import stopped during the indexing (created issue https://github.com/osm-search/Nominatim/issues/1785)

4. The indexing was resumed using:

   ./utils/setup.php --index --create-search-indices --create-country-names

5. Then faced the issue https://github.com/osm-search/Nominatim/issues/1476.

   I had to use SELECT pg_terminate_backend( ) FROM pg_stat_activity; 7-8 times.

6. After a successful setup of planet DB, the next step was to import Wikipedia and Wikidata. This was done by following steps described at https://nominatim.org/release-docs/latest/admin/Import-and-Update/#wikipediawikidata-rankings

7. The photon project was also set up on the server for testing and playing around with the code.

With the completion of server setup, I am all set to go ahead with the next phases of the project.

Open issues:

After setting up the server, I took up the following issues. This was in order to improve my understanding of the codebase and get myself more familiar with the project.

1. Took up Nominatim issue #946.(In progress)
2. Took up Photon issue #448.(PR Merged)