There are two different kinds of stored requests:
imp object. Prebid Server defines these in imp[].ext.prebid.storedrequest.Stored requests can be placed in the database or files. See below for how to set up the database. This guide assumes that new Prebid Server host companies will start with files.
Configure your server to read stored requests from the filesystem:
settings:
filesystem:
settings-filename: sample-app-settings.yaml
stored-requests-dir: stored_requests
stored-imps-dir: stored_imps
Choose an ID to reference your stored request data. Throughout this doc, replace {id} with the ID you’ve chosen.
Add the file stored_imps/{id}.json and populate it with some imp data. This will create an impression-level stored request.
{
"id": "test-imp-id",
"banner": {
"format": [
{
"w": 300,
"h": 250
},
{
"w": 300,
"h": 600
}
]
},
"ext": {
"prebid": {
"bidder": {
"appnexus": {
"placement_id": 10433394
}
}
}
}
}
Start your server and then POST to /openrtb2/auction with your chosen ID.
{
"id": "test-request-id",
"imp": [
{
"ext": {
"prebid": {
"storedrequest": {
"id": "{id}"
}
}
}
}
]
}
The auction will occur as if the HTTP request had included the content from stored_requests/{id}.json instead.
You can also store part of the imp on the server. For example:
{
"banner": {
"format": [
{
"w": 300,
"h": 250
},
{
"w": 300,
"h": 600
}
]
},
"ext": {
"prebid": {
"bidder": {
"appnexus": {
"placement_id": 10433394
}
}
}
}
}
This is not fully legal OpenRTB imp data, since it lacks an id.
However, incoming HTTP requests can fill in the missing data to complete the OpenRTB request:
{
"id": "test-request-id",
"imp": [
{
"id": "test-imp-id",
"ext": {
"prebid": {
"storedrequest": {
"id": "{id}"
}
}
}
}
]
}
If the Stored Request and the HTTP request have conflicting properties, they will be resolved with a JSON Merge Patch. HTTP request properties will overwrite the Stored Request ones.
So far, our examples have only used impression-level data. However, Stored Requests are also allowed at the top level at ext.prebid.storedrequest. These work exactly the same way, but support storing properties like timeouts and price granularity.
For example, assume the following stored-requests/{id}.json:
{
"tmax": 1000,
"ext": {
"prebid": {
"targeting": {
"pricegranularity": "low"
}
}
}
}
Then HTTP request like:
{
"id": "test-request-id",
"imp": [
"Any valid Imp data in here"
],
"ext": {
"prebid": {
"storedrequest": {
"id": "{id}"
}
}
}
}
will produce the same auction as if the HTTP request had been:
{
"id": "test-request-id",
"tmax": 1000,
"imp": [
"Any valid Imp data in here"
],
"ext": {
"prebid": {
"targeting": {
"pricegranularity": "low"
}
}
}
}
Prebid Server does allow both top-level and impression-level stored requests in the same HTTP Request. The top-level stored request will be applied first, and then the impression-level stored request.
Beware: Stored Request data will not be applied recursively. If a Stored BidRequest includes Imps with their own Stored Request IDs, then the data for the contained Stored Imps will not be resolved.
Note: However, stored requests may contain storedresponses.
Stored Requests do not need to be saved to files. Other backends are supported with different configuration options.
For PostgreSQL:
settings:
database:
type: postgres
For MySQL:
settings:
database:
type: mysql
The select query columns of stored-requests-query and amp-stored-requests-query properties should correspond to the specific format:
request for stored requests or imp for stored impressions.settings:
http:
endpoint: http://stored-requests.prebid.com
amp_endpoint: http://stored-requests.prebid.com?amp=true
Note: HTTP backend implementation always gives an empty result (with “Not supported” error inside)
for obtaining the Account or AdUnitConfig by ID for the legacy auction endpoint.
Full list of application configuration options can be found here.
If you need support for a backend that you don’t see, please contribute it.
Stored Request data can also be cached or updated while PBS is running. Conceptually, Stored Request data is managed by the following components in the code:
ApplicationSettings: Implementations of this interface pull data directly from a backend. SettingsCache: Duplicates data which the ApplicationSettings could find so that it can be accessed more quickly. CacheNotificationListener: Provides interface apply changes to Stored Request data.
ApplicationSettings and methods of updating Stored Request data at runtime can also be chosen in the the app config. At least one ApplicationSettings is required to make use of Stored Requests.
If more than one ApplicationSettings is defined, they will be ordered and used as fallback data sources. This isn’t a great idea for Prod in the long-term, but may be useful temporarily if you’re trying to transition from one backend to another.
CacheNotificationListener is used to Save or Invalidate values from the cache.
Here is an example configuration file which looks for Stored Requests first from Postgres, and then from an HTTP endpoint. It will use an in-memory LRU cache to store data locally, and poll another HTTP endpoint to listen for updates.
settings:
database:
type: postgres
host: localhost
port: 5432
dbname: database-name
user: username
password: password
stored-requests-query: SELECT accountId, reqid, requestData, 'request' as dataType FROM stored_requests WHERE reqid IN (%REQUEST_ID_LIST%) UNION ALL SELECT accountId, impid, impData, 'imp' as dataType FROM stored_requests WHERE impid IN (%IMP_ID_LIST%)
amp-stored-requests-query: SELECT accountId, reqid, requestData, 'request' as dataType FROM stored_requests WHERE reqid IN (%REQUEST_ID_LIST%)
http:
endpoint: http://stored-requests.prebid.com
amp-endpoint: http://stored-requests.prebid.com?amp=true
in-memory-cache:
cache-size: 10000
ttl-seconds: 360
http-update:
endpoint: http://stored-requests.prebid.com
amp-endpoint: http://stored-requests.prebid.com?amp=true
refresh-rate: 60000
timeout: 2000
Refresh rate can be negative or zero - in such case the data will be fetched once and never updated.