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Access to TIS fails for some users, some of the time, with the browser message ‘Service unavailable’.
TIS recovers without intervention a few minutes later; clearing . Clearing the browser cache would also restore access. This was inadvertently caused by carrying out some infrastructure changes, that amended the configuration such that it became possible for a user to have more than one ‘session’ on the go simultaneously. When one of those sessions expired, the problem was created. The TIS team have amended the configuration to prevent multiple sessions occurring, meaning this issue should not reoccurget into a state that blocked logging in.
Rather than make an immediate change to restore access for those affected users, we carefully made a “No Downtime” change, taking particular care not to disrupt access for the majority of users that were using TIS at the time. We are taking steps to mitigate this issue being triggered by any future infrastructure amendments.
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