HTTP 413 "Configuration does not fit in LMDB database" error when posting a declarative configuration in DB-less mode

When attempting to post a new configuration in DB-less mode you receive the below error:

curl -X POST http://localhost:8001/config --form config=@"kong.yaml"

HTTP/1.1 413 Request Entity Too Large
Date: Thu, 27 Aug 2026 07:17:22 GMT
Content-Type: application/json; charset=utf-8
Connection: keep-alive
X-Kong-Admin-Request-ID: SdhfUn252BkqyAbmq3DmLjZYxdDS5oV0
Content-Length: 113
Server: kong/3.14.0.0-enterprise-edition

{"message":"Configuration does not fit in LMDB database, consider raising the \"lmdb_map_size\" config for Kong"}

The corresponding Kong Gateway error log entry reads:

[error] ... [kong] config.lua:180 not enough space for declarative config, client: <client-ip>, server: kong_admin, request: "POST /config HTTP/1.1", host: "<host>:8001"

This error occurs when Kong’s DB-less/hybrid configuration store (LMDB) is configured with an insufficient map size to hold and process the new declarative configuration.

This is adjusted via the lmdb_map_size setting in kong.conf/environment variables/Helm values file, for example:

lmdb_map_size = 2048m

As an environment variable: KONG_LMDB_MAP_SIZE=2048m.

Note that lmdb_map_size now defaults to 2048m (raised from earlier, much smaller defaults in older Kong versions), so a customer hitting this error today genuinely needs a very large declarative configuration to trigger it at the default setting; if it still occurs, raise lmdb_map_size further.