asp.net - SQL Server session in CLUSTER -


can me ...

i have 3 node sql server cluster lets n1, n2 , n3. name 3 node cluster sqlclus. application connects database using name sqlclus in connections strings name.

the application uses sql server session manangement. remote desktopped n1 (which active while n2 , n3 passive) , locaiton

c:\windows\microsoft.net\framework64\v2.0.50727

i executed following command

aspnet_regsql.exe -s sqlclus -e -ssadd -sstype p

the command executed successfully. login sqlclus , see aspstate database created 2 tables.

i tested applciation uses sql server session , works fine.

now question ...

  1. if there fail on node n2 or n3 application still work ?. did not execute above command (aspnet_regsql.exe ) n2.

  2. should execute command , aspnet_regsql.exe -s sqlclus -e -ssadd -sstype p , in n2 , n3 ?

  3. what changes happens in sql server after executing above command ?. mean , there kind of service ot settings changes can seen ?.

greatly apprecite in puts regarding this....

thanks in advance...

    3.

sql server failover clustering can conceptually explained smoke-and-mirrors dns hack. thinking of clustering in familiar terms makes realize how simple technology is.

simplified description of sql server failover clustering

imagine have 2 computers: srva , srvb

you plug external hd (f:) srva, install sql server , configure store database files on f:\ (the executable under c:\program files).

unplug hd, plug srvb, install sql server , configure store database files on f:\ in exact same location.

now, create dns alias "mydbserver" points srva, plug external hd srva, , start sql server.

all until 1 day when power supply fails on srva , machine goes down.

to recover disaster following:

  1. plug external drive srvb
  2. start sql server on srvb
  3. tweak dns entry "mydbserver" point srvb.

you're , going on srvb, , client applications blissfully unaware srva failed because ever connected using name "mydbserver".

failover clustering in reality

srva , srvb cluster nodes. external hd shared san storage. 3 step recovery process happens during cluster failover , managed automatically windows failover clustering service.

what kinds of tasks need run on each sql node?

99.99% of tasks perform in sql server stored in database files on shared storage , therefore move between nodes during failover. includes creating logins, creating databases, inserts/updates/deletes on tables, sql agent jobs , else can think of. includes of tasks aspnet_regsql command performs (it nothing special database perspective).

the remaining .01% of things have done on each individual node (because aren't stored on shared storage) things applying service packs (remember executable on c:), registry settings (some sql server registry settings "checkpointed" , failover, aren't), registering 3rd party com dll's (no 1 anymore) , changing service account sql server runs under.

try yourself

if want verify aspnet_regsql doesn't need run on each node, try failing on , verify app still works. if run aspnet_regsql on each node , reference clustered name (sqlclus) over-writing database, if doesn't error out, wipe out existing data.


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