Database Reference
In-Depth Information
Server
processes
Clusterware
TICP
UDP
RDS
IP
IP over IB
Host Channel
Adapter
Switch
Figure 9-4.
RDS protocol layers
The RDS library must be linked to both Database and Grid Infrastructure binaries. Clusterware uses the TCP/IP
protocol in InfiniBand architecture too. The RDS protocol is supposed to be the lowest-resource-usage protocol, with
a latency on the order of 0.1 ms.
Relinking Protocol Library
Oracle RAC provides protocol-specific library files to link with binary. For example, libskgxpg.so file implements the
UDP protocol, and libskgxpr.so file implements the RDS protocol. So, to use the UDP protocol, Oracle Database binary
must be linked with the libskgxpg.so library. But, instead of linking directly to the protocol-specific library file, the
protocol library file is copied to the libskgxp11.so file, and then Oracle binary is linked to the libskgxp11.so file.
Database and ASM software are linked with a protocol library for cache fusion. For example, in Oracle Database
version 11g, libskgxp11.so is the library file linked with the database binary. The following
ldd
command output in the
Solaris platform shows that the libskgxp11.so file is linked to Oracle binary.
$ ldd oracle|grep skgxp
libskgxp11.so => /opt/app/product/11.2.0.2/lib/libskgxp11.so
In release 12c, an updated library file is used, and the following ldd command output shows that the libskgxp12.
so library file is linked.
$ ldd oracle|grep skgxp
libskgxp12.so => /opt/app/product/12.1.0/lib/libskgxp12.so
The relink rule in the RDBMS makes file ins_rdbms.mk of Oracle database binary can be used to specify a protocol
for cache fusion. The following ipc_g rule enables the use of the UDP protocol for cache fusion. Execution of this rule
through a make command will remove file libskgxp11.so and copy UDP-specific library file libskgxpg.so to libskgxp11.so.
ipc_g:
-$(RMF) $(LIBSKGXP)
$(CP) $(LIBHOME)/libskgxpg.$(SKGXP_EXT) $(LIBSKGXP)
rm -f /opt/app/product/12.1.0/lib/libskgxp12.so
cp /opt/app/product/12.1.0/lib/libskgxpg.so /opt/app/product/12.1.0/lib/libskgxp12.so
