The following message was received from Betfair:
"We are contacting you to make you aware of a Betfair Exchange Stream API release on the 20th & 21st March from 0630-0730 GMT
Please note that during this release there will be two pauses to the Orders Stream each lasting <60 seconds:
20/03 – Between 0630 – 0730 GMT
21/03 – Between 0630 – 0730 GMT
During these pauses the Order Stream API won’t send Order Stream updates but will return the documented 503 status message. The Market Stream API will continue to work as normal."