Brocade Communications Systems ServerIron ADX 12.4.00 Manuale Utente
ServerIron ADX Global Server Load Balancing Guide
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Weighted distribution of sites with hash-based persistence
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The ServerIron ADX sorts the IP addresses for domain www.foo.com in ascending order of the
addresses as follows.
addresses as follows.
1.1.1.42 (rank 1)Hash Weight: 1
1.1.1.43 (rank 2)Hash Weight: 1
1.1.1.44 (rank 3) Hash Weight: 2
The hash table for domain is rehashed using the algorithm described in Section 1.3. The hash
table for www.foo.com will be as follows after rehashing.
table for www.foo.com will be as follows after rehashing.
The hash-table allocation will be the same after the introduction of a new IP, on all the GSLB
controllers with the same set of IPs for the domain. At the same time, this method will provide fair
allocation to the newly introduced IP without the need for a protocol between two or more network
redundant GSLB controllers. Even if this mechanism is used for two controllers in HA, no hash table
synchronization is required between them.
controllers with the same set of IPs for the domain. At the same time, this method will provide fair
allocation to the newly introduced IP without the need for a protocol between two or more network
redundant GSLB controllers. Even if this mechanism is used for two controllers in HA, no hash table
synchronization is required between them.
Disabling rehash on introduction of new IP addresses or state change from down
to healthy
to healthy
You can disable rehash on the introduction of a new IP address or change of IP address state from
down to healthy. User would typically disable this rehash to avoid breaking the persistence when
rehashing is performed. The trade off is the new iP address will not be included in the hash table.
User will have to manually rehash at a later time to enable the new IP address to be included.
down to healthy. User would typically disable this rehash to avoid breaking the persistence when
rehashing is performed. The trade off is the new iP address will not be included in the hash table.
User will have to manually rehash at a later time to enable the new IP address to be included.
If the rehashing on state change or introduction of a new IP is disabled, and such an event occurs,
then a message stating that the ServerIron ADX needs to be rehashed at a later time will be
displayed.
then a message stating that the ServerIron ADX needs to be rehashed at a later time will be
displayed.
Rehash: change in hash weight
ServerIron ADX will rehash the hash table for a domain when the hash weight for an IP configured
for the domain is changed. The rehashing will be similar to that described in Section 1.4.
for the domain is changed. The rehashing will be similar to that described in Section 1.4.
Disabling rehash on change in hash weight configuration
You can disable rehash on change in hash weight configuration for domain IP addresses. User
would typically disable this rehash to avoid breaking the persistence when rehashing is performed
due to change in hash weight. The trade-off is the new weight for the IP address will not be
reflected in the hash bucket assignments for the hash table. User will have to manually rehash at a
later convenient time to enable the new weight to be used in hash table assignments.
would typically disable this rehash to avoid breaking the persistence when rehashing is performed
due to change in hash weight. The trade-off is the new weight for the IP address will not be
reflected in the hash bucket assignments for the hash table. User will have to manually rehash at a
later convenient time to enable the new weight to be used in hash table assignments.
Configuring distribution of sites with hash-based persistence
With the weighted hash-based GSLB persistence, users will be able to define hash weights for IPs
for a domain. The hash buckets will be distributed among the domain IP addresses in proportion to
these weights.
for a domain. The hash buckets will be distributed among the domain IP addresses in proportion to
these weights.
The new command line interface needed for weighted hash-based GSLB persistence is described
below.
below.
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1
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255
.42
.43
.44
.44
.44