The "BlockingQuotaEnforcer" are informational messages printed within the Collectors logs and do not necessarily mean your Collector is being throttled.
2015-03-03 18:16:44,394 [QuotaEnforcer] INFO com.sumologic.scala.collector.quota.BlockingQuotaEnforcer - BlockingQuotaEnforcer(Senders) - Requested: 1.26 KB (0.13 KB/s). Remaining capacity: 0.73 MB (until Tue Mar 03 18:05:14 PST 2015)
The "BlockingQuotaEnforcer" is the mechanism the service uses to determine if an account should be throttled based on the contract terms of the account and the overall amount of data that is being sent across your Collectors. These messages will be outputted within the Collector logs on a regular basis, every 10 minutes, and show how much volume (quota) the Collector is currently able to send to the service for a period of time. These messages have two important pieces of information:
Requested - This is the amount of data the Collector has sent to the service since the last quota message.
Requested: 1.26 KB (0.13 KB/s)
Remaining capacity - This is the amount of data the Collector can currently send to the service based on the current ingest rates. The time in this value is the next time the Collector can request additional quota.
Remaining capacity: 0.73 MB (until Tue Mar 03 18:05:14 PST 2015)
Only if the Remaining capacity has dropped close to "0.0 MB" and the date in this message is showing a time that is in the future, compared to the time the message was created, should you need to be concerned about any throttling occurring within the account.