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Navigating the API logs:

apps/docs/content/troubleshooting/discovering-and-interpreting-api-errors-in-the-logs-7xREI9.mdx

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Original Source

A complimentary guide was made for the Postgres logs

Navigating the API logs:

The Database API is powered by a PostgREST web-server, recording every request to the API Edge Network logs. To precisely navigate them, use the Log Explorer. These logs are managed through Logflare and can be queried with a subset of BigQuery SQL syntax.

The log table that contains API requests is edge_logs.

Notably, it contains:

fielddescription
event_messagethe log's message
timestamptime event was recorded
request metadatametadata about the REST request
response metadatametadata about the REST response

The request and response columns are arrays in the metadata field and must be unnested. This is done with a cross join.

Unnesting example

sql
select
  -- the event message does not require unnesting
  event_message,
  -- unnested status_code column from metadata.response field
  status_code
from
  edge_logs
  -- Unpack data stored in the 'metadata' field
  cross join unnest(metadata) as metadata
  -- After unpacking the 'metadata' field, extract the 'response' field from it
  cross join unnest(response) as response;

The most useful fields for debugging are:

NOTE: not every field is included below. For a full list, check the API Edge field reference in the Log Explorer

Request object

Cloudflare geographic data:

Suggested use cases:

  • Detecting abuse from a specific region
  • Detecting activity spikes from certain regions
ColumnDescriptionSample value
request.cf.cityRequester's cityMunich
request.cf.countryRequester's countryDE
request.cf.continentRequester's continentEU
request.cf.regionRequester's regionBavaria
request.cf.latitudexRequester's latitude48.10840
request.cf.longitudeRequester's longitude11.61020
request.cf.timezoneRequester's timezoneEurope/Berlin

Unnesting example:

sql
select
  city
from
  edge_logs
-- Unpack 'metadata' field
cross join unnest(metadata) AS metadata
-- unpack 'request' from 'metadata'
cross join unnest(request) AS request;
-- unpack 'cf' from 'request'
cross join unnest(cf) AS cf;

IP and browser/environment data:

Suggested use cases:

  • Detecting request behavior from IP
  • Detecting abuse by IP
  • Detecting errors by user_agent
ColumnDescriptionSample value
request.headers.cf_connecting_ipRequester's IP80.81.18.138
request.headers.user_agentRequester's browser or app environmentMozilla/5.0 (Linux; Android 11; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Mobile Safari/537.36

Unnesting example:

sql
select
  cf_connecting_ip
from
  edge_logs
-- Unpack 'metadata' field
cross join unnest(metadata) AS metadata
-- unpack 'request' from 'metadata'
cross join unnest(request) AS request;
-- unpack 'headers' from 'request'
cross join unnest(headers) AS headers;

Query type and formatting data:

Suggested use cases:

  • identify problematic queries
  • identify unusual behavior by authenticated users
ColumnDescriptionSample value
request.methodRequest Method (PATCH, GET, PUT...)GET
request.urlRequest URL, which contains the PostgREST formatted queryhttps://yuhplfrsdxxxtldakizi.supabase.co/rest/v1/users?select=username&id=eq.63b6190e-214f-4b8a-b72d-3af6e1921411&limit=1
request.sb.auth_usersauthenticated user's ID63b6190e-214f-4b8a-b72d-3af6e1921411

Unnesting example:

sql
select
  method,
  url,
  auth_users
from
  edge_logs
-- Unpack 'metadata' field
cross join unnest(metadata) AS metadata
-- unpack 'request' from 'metadata'
cross join unnest(request) AS request;
-- unpack 'sb' from 'request'
cross join unnest(sb) AS sb;

Response object

Status code:

Suggested use cases:

  • detect success/errors
ColumnDescriptionSample value
response.status_codeResponse status code (200, 404, 500...)404

Unnesting example:

sql
select
  status_code
from
  edge_logs
  -- Unpack 'metadata' field
  cross join unnest(metadata) as metadata
  -- unpack 'response' from 'metadata'
  cross join unnest(response) as response;

Finding errors

API level errors

The metadata.request.url contains PostgREST formatted queries.

For example, the following call to the JS client:

js
let { data: countries, error } = await supabase.from('countries').select('name')

translates to calling the following endpoint:

bash
https://<project ref>.supabase.co/rest/v1/countries?select=name

You can use regex (Advanced Regex Guide) to find the objects related to your query. Try isolating by:

  • function names
  • column names
  • table names
  • query methods (select, insert, ...)

Example:

sql
select
  cast(timestamp as datetime) as timestamp,
  status_code,
  url,
  event_message
from edge_logs
cross join unnest(metadata) as metadata
cross join unnest(response) AS request;
cross join unnest(response) AS response;
where
  -- find all errors
  status_code >= 400
    and
  -- find queries featuring the a specific <table_name> and <column_name>
  (
    regexp_contains(url, '<table_name>')
    and
    regexp_contains(event_message, '<column_name1>|<column_name2>')
  )

PostgREST has an error reference table that you can use to interpret status codes.

Database-level errors

However, some errors that are reported through the Database API occur at the Postgres level. If it is not clear which error occurred you should reference the timestamp of the error and try to see if you can find it in the Postgres logs.

sql
select
  cast(postgres_logs.timestamp as datetime) as timestamp,
  error_severity,
  user_name,
  query,
  detail,
  sql_state_code,
  event_message
from postgres_logs
  cross join unnest(metadata) as metadata
  cross join unnest(metadata.parsed) as parsed
where
  -- filter only for error events
  regexp_contains(parsed.error_severity, 'ERROR|FATAL|PANIC')
    and
  -- All DB API requests are registered as the authenticator role
  parsed.user_name = 'authenticator'
    and
  -- find failed queries featuring the function <function_name>
  regexp_contains(parsed.query, '<function_name>')
    and
  -- limit the time of the search to be around the time of the failed API request
postgres_logs.timestamp between '2024-04-15 10:50:00' AND '2024-04-15 10:50:27'
order by
 timestamp desc
limit 100;

Like PostgREST, Postgres has a reference table for interpreting error codes.

PostgREST server and Cloudflare errors

In some cases, errors may emerge because of Cloudflare or PostgREST server errors. For 500 and above errors, you may want to check your PostgREST logs and the Cloudflare docs.)

Practical examples:

Find All Errors:

sql
select
  cast(timestamp as datetime) as timestamp,
  status_code,
  event_message,
  path
from
  edge_logs
  cross join unnest(metadata) as metadata
  cross join unnest(response) as response
  cross join unnest(request) as request
where
  -- find all errors
  status_code >= 400
  and regexp_contains(path, '^/rest/v1/');
-- only look at DB API

Group errors by path and code:

sql
select
  status_code,
  path,
  count(path) as reoccurrence_per_path
from
  edge_logs
  cross join unnest(metadata) as metadata
  cross join unnest(response) as response
  cross join unnest(request) as request
where
  -- find all errors
  status_code >= 400
  and regexp_contains(path, '^/rest/v1/') -- only look at DB API
group by path, status_code
order by reoccurrence_per_path;

Find requests by region:

sql
select
  path,
  region,
  count(region) as region_count
from
  edge_logs
  cross join unnest(metadata) as metadata
  cross join unnest(request) as request
  cross join unnest(cf) as cf
where
  -- only look at DB API
  regexp_contains(path, '^/rest/v1/')
group by region, path
order by requester_region_count;

Find total requests by IP:

sql
select
  cf_connecting_ip as ip,
  count(cf_connecting_ip) as ip_count
from
  edge_logs
  cross join unnest(metadata) as metadata
  cross join unnest(request) as request
  cross join unnest(headers) as headers
  cross join unnest(cf) as cf
  cross join unnest(response) as response
where regexp_contains(path, '^/auth/v1/')
group by ip
order by ip_count;

Search frequented query paths by authenticated user:

sql
select
  -- only available for front-end clients
  auth_users,
  path,
  count(auth_users) as ip_count
from
  edge_logs
  cross join unnest(metadata) as metadata
  cross join unnest(request) as request
  cross join unnest(sb) as sb
where
  -- only look at DB API
  regexp_contains(path, '^/rest/v1/')
group by auth_users, path;