Re: Patch: Implement failover on libpq connect level.

On Fri, 26 Aug 2016 10:10:33 +0530
Mithun Cy <mithun.cy@enterprisedb.com> wrote:

> On Thu, Mar 17, 2016 at 4:47 AM, David Steele <david@pgmasters.net>
> wrote:
> >Since there has been no response from the author I have marked this
> >patch  
> "returned with feedback".  Please feel free >to resubmit for 9.7!
> I have started to work on this patch, and tried to fix some of the
> issues discussed above. The most recent patch 06 has fixed many
> issues which was raised previously which include indefinite looping,
> crashes. And, some of the issues which remain pending are.
> 
> 1. Connection status functions PQport, PQhost do not give
> corresponding values of established connection. -- Have attached the
> patch for same.
> 
> 2. Default value of readonly parameter is 0, which means should
> connect to master only. So absence of parameter in connection string
> in simple cases like "./psql -p PORT database" fails to connect to
> hot standby server.  I think since if readonly=1 means connect to
> any. and readonly=0 means connect to master only, we should change
> the default value  to 1, to handle the cases when parameter is not
> specified.
> 
> JFYI Interestingly PostgreSql JDBC driver have following options
> targetServerType=any|master|slave|preferSlave for same purpose.
> 
> Also did a little bit of patch clean-up.
> 
> Also found some minor issues related to build which I am working on.
> 1. make check-world @src/interfaces/ecpg/test/connect fails with
> following error:
> gcc -Wall -Wmissing-prototypes -Wpointer-arith
> -Wdeclaration-after-statement -Wendif-labels
> -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing
> -fwrapv -fexcess-precision=standard -g -O0 -pthread -D_REENTRANT
> -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS test1.o -L../../ecpglib
> -L../../pgtypeslib -L../../../../../src/interfaces/libpq
> -L../../../../../src/port -L../../../../../src/common -Wl,--as-needed
> -Wl,-rpath,'/home/mithun/edbsrc/patch6bin/lib',--enable-new-dtags
> -lecpg -lpgtypes -lpq -lpgcommon -lpgport -lz -lrt -lcrypt -ldl -lm
> -o test1 ../../../../../src/interfaces/libpq/libpq.so: undefined
> reference to `pg_usleep'
> collect2: error: ld returned 1 exit status
> make[3]: *** [test1] Error 1
> make[3]: Leaving directory `/home/mithun/mynewpost/p1/
> src/interfaces/ecpg/test/connect'
> 
> patch has used pg_usleep() which is in L../../../../../src/port  I
> think dependency is not captured rightly.
> 
> Thanks and Regards
> Mithun C Y
> EnterpriseDB: http://www.enterprisedb.com