Capping Analytics Data Storage

Last updated: 3 minutes read.

Tyk Gateways can generate a lot of analytics data. A guideline is that for every 3 million requests that your Gateway processes it will generate roughly 1GB of data.

If you have Tyk Pump set up with the aggregate pump as well as the regular MongoDB pump, then you can make the tyk_analytics collection a capped collection. Capping a collection guarantees that analytics data is rolling within a size limit, acting like a FIFO buffer which means that when it reaches a specific size, instead of continuing to grow, it will replace old records with new ones.

Note

If you are using DocumentDB, capped collections are not supported. See here for more details.

The tyk_analytics collection contains granular log data, which is why it can grow rapidly. The aggregate pump will convert this data into a aggregate format and store it in a separate collection. The aggregate collection is used for processing reporting requests as it is much more efficient.

If you’ve got an existing collection which you want to convert to be capped you can use the convertToCapped MongoDB command.

If you wish to configure the pump to cap the collections for you upon creating the collection, you may add the following configurations to your uptime_pump_config and / or mongo.meta objects in pump.conf.

"collection_cap_max_size_bytes": 1048577,
"collection_cap_enable": true

collection_cap_max_size_bytes sets the maximum size of the capped collection. collection_cap_enable enables capped collections.

If capped collections are enabled and a max size is not set, a default cap size of 5Gib is applied. Existing collections will never be modified.

Note

An alternative to capped collections is MongoDB’s Time To Live indexing (TTL). TTL indexes are incompatible with capped collections. If you have set a capped collection, a TTL index will not get created, and you will see error messages in the MongoDB logs. See MongoDB TTL Docs for more details on TTL indexes.

Time Based Cap in single tenant environments

If you wish to reduce or manage the amount of data in your MongoDB, you can add an TTL expire index to the collection, so older records will be evicted automatically.

Note

Time based caps (TTL indexes) are incompatible with already configured size based caps.

Run the following command in your preferred MongoDB tool (2592000 in our example is 30 days):

db.tyk_analytics.createIndex( { "timestamp": 1 }, { expireAfterSeconds: 2592000 } )

This command sets expiration rule to evict all the record from the collection which timestamp field is older then specified expiration time.

Time Based Cap in multi-tenant environments

When you have multiple organisations, you can control analytics expiration on per organisation basis. This technique also use TTL indexes, as described above, but index should look like:

db.tyk_analytics.createIndex( { "expireAt": 1 }, { expireAfterSeconds: 0 } )

This command sets the value of expireAt to correspond to the time the document should expire. MongoDB will automatically delete documents from the tyk_analytics collection 0 seconds after the expireAt time in the document. The expireAt will be calculated and created by Tyk in the following step.

Step 2. Create an Organisation Quota

curl --header "x-tyk-authorization: {tyk-gateway-secret}" --header "content-type: application/json" --data @expiry.txt http://{tyk-gateway-ip}:{port}/tyk/org/keys/{org-id}

Where context of expiry.txt is:

{
  "org_id": "{your-org-id}",
  "data_expires": 86400
}

data_expires - Sets the data expires to a time in seconds for it to expire. Tyk will calculate the expiry date for you.

Size Based Cap

Add the Size Cap

Note

The size value should be in bytes, and we recommend using a value just under the amount of RAM on your machine.

Run this command in your MongoDB shell:

use tyk_analytics
db.runCommand({"convertToCapped": "tyk_analytics", size: 100000});

Adding the Size Cap if using a mongo_selective Pump

The mongo_selective pump stores data on a per organisation basis. You will have to run the following command in your MongoDB shell for an individual organisation as follows.

db.runCommand({"convertToCapped": "z_tyk_analyticz_<org-id>", size: 100000});