SCAN IP 解释

Summary of points about SCAN:

• SCAN Name will represent the cluster in the network. 
• SCAN used by clients to connect to any database in the cluster.
• SCAN is a GSD resource, which is managed by CRS.
• SCAN provides a single domain name (via DNS), allowing end-users to address a RAC cluster as-if it were a single IP address.
• Removes the requirement to change the client connection if cluster changes.
• Load balances across the instances providing a service. SCAN listener selects least loaded node.
• SCAN requires a DNS entry or GNS to be used.
• SCAN is an alternative to the transparent application failover (TAF) for automatic load balancing.
• Provides failover between instances.
• SCAN VIP/LISTENER will failover to another node in the cluster.
• Clients do not require VIP information.
• Must resolve to at least one address on the public network.
• SCAN provides location independence for the databases.
• Allow clients to use EZConnect or JDBC connections.
• SCAN Listener would forward the request to local listener that’s running on VIPs.
• Each cluster will have 3 SCAN listeners, each having a SCAN VIP defined as cluster resources.
• Instance registers with local listener on its node. Database “REMOTE_LISTENER” registers instances with all SCAN listeners.
• SCAN listeners on each node in the cluster, which are not replacements for a regular listener.
• PMON process of each instance registers the database services with the default listener on the local node and with each SCAN listener, which is specified by the REMOTE_LISTENER database parameter.
• Client queries DNS to resolve to SCAN.

 

SCAN (Single Client Access Name) commands in Oracle RAC

 

cluvfy comp scan -> Use the cluvfy comp scan component verification command to check the Single Client Access Name (SCAN) configuration.

 

crsctl status resource -w "TYPE = ora.scan_listner.type"

 

SCAN:

srvctl add scan -n scan_name [-k network_number] [-S subnet/netmask[/if1[|if2|...]]]

#srvctl add scan -n scan.mycluster.example.com   -- Adds new SCAN information for a cluster

 

srvctl remove scan [-f]   -- Removes SCAN information

srvctl remove scan

srvctl remove scan -f

 

srvctl start scan [-i ordinal_number] [-n node_name]

srvctl start scan

srvctl start scan -i 1 -n node1

 

srvctl stop scan [-i ordinal_number] [-f]

srvctl stop scan

srvctl stop scan -i 1

 

srvctl status scan [-i ordinal_number]

srvctl status scan

srvctl status scan -i 1

 

srvctl enable scan [-i ordinal_number]

srvctl enable scan

srvctl enable scan -i 1

 

srvctl disable scan [-i ordinal_number]

srvctl disable scan

srvctl disable scan -i 3

 

srvctl config scan [-i ordinal_number]   -- Shows the current SCAN configuration

srvctl config scan

srvctl config scan -i 2

 

srvctl modify scan -n scan_name

srvctl modify scan -n scan1
-- Modifies SCAN information (used when changing SCAN to DNS after initially using /etc/hosts)

 

srvctl relocate scan -i ordinal_number [-n node_name]

srvctl relocate scan -i 2 -n node2

 

ordinal_number=1,2,3 --> this refers to the SCAN VIPs

 

Scan_listener:

srvctl add scan_listener [-l lsnr_name_prefix] [-s] [-p "[TCP:]port_list[/IPC:key][/NMP:pipe_name][/TCPS:s_port] [/SDP:port]"]

#srvctl add scan_listener -l myscanlistener   -- Adds a new SCAN listener for a cluster on the default port of 1521

#srvctl add scan_listener -p 1565         -- Adds a new SCAN listener on a different port

 

srvctl remove scan_listener [-f]

srvctl remove scan_listener        -- Removes the SCAN listener

srvctl remove scan_listener -f

 

srvctl start scan_listener [-n node_name] [-i ordinal_number]

srvctl start scan_listener

srvctl start scan_listener -i 1

 

srvctl stop scan_listener [-i ordinal_number] [-f]

srvctl stop scan_listener

srvctl stop scan_listener -i 3

 

srvctl status scan_listener [-i ordinal_number]

srvctl status scan_listener

srvctl status scan_listener -i 1

 

srvctl enable scan_listener [-i ordinal_number]

srvctl enable scan_listener

srvctl enable scan_listener -i 2

 

srvctl disable scan_listener [-i ordinal_number]

srvctl disable scan_listener

srvctl disable scan_listener -i 1

 

srvctl config scan_listener [-i ordinal_number]  -- Shows the existence and port numbers for the SCAN listeners

srvctl config scan_listener

srvctl config scan_listener -i 3

 

srvctl modify scan_listener {-p [TCP:]port[/IPC:key][/NMP:pipe_name] [/TCPS:s_port][/SDP:port] | -u }

srvctl modify scan_listener –u -- Modifies the SCAN listener information to match the new SCAN VIP information

srvctl modify scan_listener -p 1521

 

srvctl relocate scan_listener -i ordinal_number [-n node_name]

srvctl relocate scan_listener -i 1

 

ordinal_number=1,2,3

 

GNS (Grid Naming Service):

srvctl add gns -i ip_address -d domain

srvctl add gns -i 192.124.16.96 -d cluster.mycompany.com

 

srvctl remove gns [-f]

srvctl remove gns

 

srvctl start gns [-l log_level] [-n node_name]

srvctl start gns

 

srvctl stop gns [-n node_name [-v] [-f]

srvctl stop gns

 

srvctl status gns [-n node_name]

srvctl status gns

 

srvctl enable gns [-n node_name]

srvctl enable gns

 

srvctl disable gns [-n node_name]

srvctl disable gns -n devnode2

 

srvctl config gns [-a] [-d] [-k] [-m] [-n node_name] [-p] [-s] [-V] [-q name] [-l] [-v]

srvctl config gns -n lnx03

 

srvctl modify gns [-i ip_address] [-d domain]

srvctl modify gns -i 192.100.010.007

 

srvctl relocate gns [-n node_name]

srvctl relocate gns -n node2

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