newsite.so

berkeley db 4.6.21的源码。berkeley db是一个简单的数据库管理系统

m4_comment([$Id: newsite.so,v 1.7 2006/08/24 17:58:53 bostic Exp $])

m4_ref_title(m4_db Replication,
    Connecting to a new site,, rep/comm, rep/elect)

m4_p([dnl
To add a new site to the replication group all that is needed
is for the client member to join.  m4_db will perform an
internal initialization from the master to the client automatically
and will run recovery on the client to bring it up to date
with the master.])

m4_p([dnl
For applications that use the Base replication API, connecting to a
new site in the replication group happens whenever the
m4_refT(rep_message) returns m4_ref(DB_REP_NEWSITE).  The application
should assign the new site a local environment ID number, and all future
messages from the site passed to m4_ref(rep_message) should include that
environment ID number.  It is possible, of course, for the application
to be aware of a new site before the return of m4_ref(rep_message) (for
example, applications using connection-oriented protocols are likely to
detect new sites immediately, while applications using broadcast
protocols may not).])

m4_p([dnl
Regardless, in applications supporting the dynamic addition of database
environments to replication groups, environments joining an existing
replication group may need to provide contact information.  (For
example, in an application using TCP/IP sockets, a DNS name or IP
address might be a reasonable value to provide.)  This can be done using
the m4_arg(cdata) parameter to the m4_refT(rep_start).  The information
referenced by m4_arg(cdata) is wrapped in the initial contact message
sent by the new environment, and is provided to the existing members of
the group using the m4_arg(rec) parameter returned by m4_ref(rep_message).
If no additional information was provided for m4_db to forward to the
existing members of the group, the m4_arg(data) field of the m4_arg(rec)
parameter passed to the m4_refT(rep_message) will be NULL after
m4_ref(rep_message) returns m4_ref(DB_REP_NEWSITE).])

m4_p([dnl
Replication Manager automatically distributes contact information using
the mechanisms previously described.])

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