Operator side issues, circuit shaking, authentication interface fluctuations and account flow, are not variables that can be controlled by the campus network.
Make a real decision whether or not a project is“Clear.”It's never been an anomaly, but it's:
The campus network Authentication & Billing system will trigger a large-scale concentration of wires when the dialling anomaly occurs.
A lot of systems, exactly on this point.
Why is an anomaly most likely to trigger?“Focus on the line.”
The centralization of the line is not an accident, but a corollary to the design of the system.
Among the large number of problematic projects, three characteristics are usually present:
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Dial status is strongly tied to user online status
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The dialup failed to determine the user's downline
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All sessions share the same dial-up logic
In the event of an anomaly in the operator ' s dial interface, the system will do the same action at very short notice:
Batch recovery session, forced downline, dialling。
The result is the scene that management was most afraid to see:
The entire building of the dormitories, and even the school complex, is being cut off simultaneously.
II. The network of mature campuses Authentication & Billing First Principle: Subscription≠Online Status
The blog is a part of the real long-term network of campuses, Authentication & Billing.The dial status is never equal to the user's online status.。
At least three types of status are distinguished within the system:
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User Online Status
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Session Active Status
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Dial channel status
The dialling is abnormal. It only affects.“Channel Status”，Could not close temporary folder: %s。
This is the first line of defense to avoid a centralization.
III. THE REAL CATEGORY OF DETERMINATION, NOT“Failure/ Success”Bicentile
Many systems have a rough understanding of the sub-description, with only two situations: success and failure.
In the mature campus network Authentication & Billing, dialling anomalies are broken down into at least the following categories:
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It's a temporary anomaly.
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Operator interface vibrating
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Authentication delay timeout
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Account level is abnormal
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Single account is restricted.
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The bill number is temporarily blocked.
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Export level anomaly
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An export is not available as a whole.
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A operator's chain is volatile.
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System-side error
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Heart attack.
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Postponement delay
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Only if you tell the difference between an anomaly and a system.“A lot of users were injured.”。
Core design I to avoid centralizing the line: abnormal delay determination mechanism
In the mature campus network Authentication & Billing system, the government has been able to provide a more efficient and effective response to the problem.The dialysis is never instantaneous.。
The system will introduce a key design:
Anomalous buffer window
The specific logic is:
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First dialing anomaly. → Mark, do not process users
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Continuous anomaly reached threshold → Downgraded processing
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It's going to be a very bad time. → Trigger to switch or recycle
This window of time, often only takes a few dozen seconds, but it's enough to filter 80 percent of the instant abnormality.
Core design II: stock users“Protection mechanisms”
A very important, but often overlooked principle is:
The dialling anomaly prioritizes the addition of users rather than those already online.
The mature campus network Authentication & Billing system usually uses the following strategies when dialling anomalies:
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Pause the dialyration of new sessions
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Maintain existing session and continue forwarding
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Do not force offline stock users
In other words:
Jean.“The guy who came in later, slow down.”Not“Kick off the people already online.”。
VI. CORE DESIGN III: APPLICATION OF ACCOUNTS“Batch Melting”
When an anomaly is recognized as a account level problem, the system does not process all accounts at once.
But it's:
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Group by account
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Melting by Usage Rate
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Keep a percentage of available accounts
The benefits of this are:
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It won't show.“All access routes are disabled at the same time.”
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The system keeps the exits.
This is a lot of big college projects that can be assigned to abnormalities.“It doesn't look like anything happened.”The key reason.
VII. How to avoid the deduction of fees in abnormally high cases
The concentration of the wires is a more deadly risk than the network problem:Fee disputes。
The mature campus network Authentication & Billing system usually enters the protective mode during the de-alerting anomaly:
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Pause abnormal time period
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Delay settlement
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Automatically compensate for anomalies
And that's why some projects are still going on after the anomaly.“Zero complaints”Others may give rise to a large number of rights.
VIII. FREEDOM OF IMMUNIITY: A dialling anomaly, no one is offline
At a college, the operator's interface was abnormal at night peaks for about 2 minutes:
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Some new users cannot be connected immediately
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All online users are fully functional
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No concentration, no whole dorm.
The ex post facto system log shows:
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The anomaly is recognised as a instant interface fluctuations
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Untriggered session recovery
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No re-dialing was activated.
Throughout the process, the campus network Authentication & Billing system did only one thing:
Stabilize the current situation and refuse to expand its reach.
IX. WHY A LOT OF SYSTEMS“Full”But I can't hold it back once.
The reason is often simple:
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All states are strongly tied.
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All anomalies are in effect immediately.
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Same strategy for all users
The system is well performed in the demonstration environment and extremely fragile in its real campus operation.
X. Return to the product itself
A really mature campus network Authentication & Billing, not by“No problem.”To survive, but to live by:
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Do not expand when problems arise
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No secondary disasters when an anomaly occurs
Producing companies like NatShell, which have long-term deep-farming campus networks, often do a lot of things with sub-design anomalies, state isolation, protection mechanisms.“Unseen Design”Because only after a real operation will the system know:
It's not terrible to fall off the line.