Bizdelnick писал(а): ↑29.01.2014 10:12
BAF писал(а): ↑29.01.2014 07:41
It is possible during a prolonged failure to tell the remaining server that the other server is down, in which case the remaining server will (over time) reclaim all the addresses the other server had available for allocation, and begin to reuse them. This is called putting the server into the PARTNER-DOWN state.
То есть, я так понимаю, надо ему это явно сказать, а не ждать, пока сам догадается.
я понял что он должен перейти в состояние PARTNER-DOWN с течением времени или можно это сделать вручную через omapi, но это же все делается для отказоустойчивой конфигурации, и если у меня сервер партнер выйдет из строя а я буду на мальдивах, мне что вручную заходить по ssh и переводить его в это состояние? Это бред, так не должно быть. Но возможно это так и есть, что весьма печально.
Помогите разобраться. Вот что я нарыт
тут
Цытирую фрагмент
9.9.1. Upon entry to COMMUNICATIONS-INTERRUPTED state
When a server enters COMMUNICATIONS-INTERRUPTED state, if it has been
configured to support an automatic transition out of COMMUNICATIONS-
INTERRUPTED state and into PARTNER-DOWN state (i.e., a "safe period"
has been configured, see section 10), then a timer MUST be started
for the length of the configured safe period.
Тут я так понял (у меня engnlish is bad)) говорится, что есть некий "safe period" который должен быть сконфигурирован и по истечению которого сервер из состояния COMMUNICATIONS-INTERRUPTED перейдет в PARTNER-DOWN. Я правильно понял?
Если да то вот 10 пункт:
Код: Выделить всё
10. Safe Period
Due to the restrictions imposed on each server while in
COMMUNICATIONS-INTERRUPTED state, long-term operation in this state
is not feasible for either server. One reason that these states
exist at all, is to allow the servers to easily survive transient
network communications failures of a few minutes to a few days
(although the actual time periods will depend a great deal on the
DHCP activity of the network in terms of arrival and departure of
DHCP clients on the network).
Eventually, when the servers are unable to communicate, they will
have to move into a state where they no longer can re-integrate
without some possibility of a duplicate IP address allocation. There
are two ways that they can move into this state (known as PARTNER-
DOWN).
They can either be informed by external command that, indeed, the
partner server is down. In this case, there is no difficulty in mov-
ing into the PARTNER-DOWN state since it is an accurate reflection of
reality and the protocol has been designed to operate correctly (even
during reintegration) as long as, when in PARTNER-DOWN state the
partner is, indeed, down.
The more difficult scenario is when the servers are running unat-
tended for extended periods, and in this case an option is provided
to configure something called a "safe-period" into each server. This
OPTIONAL safe-period is the period after which either the primary or
secondary server will automatically transition to PARTNER-DOWN from
COMMUNICATIONS-INTERRUPTED state. If this transition is completed
and the partner is not down, then the possibility of duplicate IP
address allocations will exist.
The goal of the "safe-period" is to allow network operations staff
some time to react to a server moving into COMMUNICATIONS-INTERRUPTED
state. During the safe-period the only requirement is that the net-
work operations staff determine if both servers are still running --
and if they are, to either fix the network communications failure
between them, or to take one of the servers down before the expira-
tion of the safe-period.
The length of the safe-period is installation dependent, and depends
in large part on the number of unallocated IP addresses within the
subnet address pool and the expected frequency of arrival of
previously unknown DHCP clients requiring IP addresses. Many
environments should be able to support safe-periods of several days.
During this safe period, either server will allow renewals from any
existing client. The only limitation concerns the need for IP
addresses for the DHCP server to hand out to new DHCP clients and the
need to re-allocate IP addresses to different DHCP clients.
The number of "extra" IP addresses required is equal to the expected
total number of new DHCP clients encountered during the safe period.
This is dependent only on the arrival rate of new DHCP clients, not
the total number of outstanding leases on IP addresses.
In the unlikely event that a relatively short safe period of an hour
is all that can be used (given a dearth of IP addresses or a very
high arrival rate of new DHCP clients), even that can provide sub-
stantial benefits in allowing the DHCP subsystem to ride through
minor problems that could occur and be fixed within that hour. In
these cases, no possibility of duplicate IP address allocation
exists, and re-integration after the failure is solved will be
automatic and require no operator intervention.
Я так и не понял как конфигурить это период. Помогите понять смысл перевода товарищи.
Забыл сказать что в состоянии COMMUNICATIONS-INTERRUPTED он считает что сервер партнер работает просто с ним нет связи и не выделяет адреса, которые были backucp у партнера. Как раз как у меня. Остается только понять или сконфигурить, что бы он переходил в состояние DOWN и ообеспечивал клиентов всем свободным пулом. Но как?
Поправите меня, если я не прав, буду тока рад.
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