Issues with re-setting the provider

Raghu, wsrep_provider_options loss is expected (although inconvenient). I have reported a more targeted ticket about it here: https://bugs.launchpad.net/codership-mysql/5.6/+bug/1260290

Come to think of it, the fix to it could also fix this one.

@Alex,

a)
The loss of configuration is one of the issues.

What about the other one -

""
131212 15:53:20 [Warning] WSREP: Unknown parameter 'pc.bootstrap'
131212 15:53:20 [ERROR] WSREP: Set options returned 7
131212 15:53:20 [Note] WSREP: refresh_provider_options: pc.bootstrap=1;
""

This suggests non-initialization of pc component or failure to
set it.

b) Next, when you say set it on command line, do you want the
entire wsrep_provider_options or just the ones set in my.cnf (so
others are initialised to compiled defaults) to be specified as
set global wsrep_provider_options=''. I guess the latter?

Raghu,
a) setting pc.bootstrap is meaningful only after connecting to a non-primary component. I.e. you need to set wsrep_cluster_address first (plus necessary wsrep_provider_options).
b) yes, just what is different from defaults.

in general, the process of updating a provider is
1. reload provider (previous wsrep_provider_options value is gone. use built-in value in galera code)
2. set wsrep_provider_options
3. set wsrep_clutser_address (connect to cluster and then start replication)

Most parameters in wsrep_provder_options should be set *before* connecting to cluster, like gcache.*, repl.* etc. However some parameters could only be set *after* connecting to cluster. AFAIK, these parameters include
a. protonet.*
b. socket.*
c. gmcast.*
d. evs.*
e. pc.*

So if you are gonna to set pc.bootstrap=1, you can only do it after you set wsrep_clutser_address .

@Yan,

It works but I noticed this:

MySQL [(none)]> set global wsrep_provider='none';
Query OK, 0 rows affected (2.02 sec)

MySQL [(none)]> set global wsrep_provider='/usr/lib64/libgalera_smm.so';
Query OK, 0 rows affected (2.03 sec)

MySQL [(none)]> set global wsrep_provider_options="gmcast.listen_addr=tcp://127.0.0.1:4010"; -- Fails due to no cluster address, this is OK
ERROR 1210 (HY000): Incorrect arguments to SET
MySQL [(none)]>
MySQL [(none)]> set global wsrep_cluster_address='gcomm://127.0.0.1:5010,127.0.0.1:6010'; --- Fails (in log), but lets ignore that for now.
Query OK, 0 rows affected (35.02 sec)

MySQL [(none)]> set global wsrep_cluster_address='gcomm://';
Query OK, 0 rows affected (2.00 sec)

MySQL [(none)]> set global wsrep_provider_options="gmcast.listen_addr=tcp://127.0.0.1:4010"; ------ This fails.
ERROR 1210 (HY000): Incorrect arguments to SET

It fails with:
================

2014-04-30 10:04:30 13562 [Note] WSREP: Nobody is waiting for SST.
2014-04-30 10:04:34 13562 [Warning] WSREP: error setting param gmcast.listen_addr to value tcp://127.0.0.1:4010: can't change value for 'gmcast.listen_addr' during runtime: 1 (Operation not permitted)
         at gcomm/src/gmcast.cpp:set_param():1640
2014-04-30 10:04:34 13562 [Warning] WSREP: Setting parameter 'gmcast.listen_addr' to 'tcp://127.0.0.1:4010' failed: Setting 'gmcast.listen_addr' to 'tcp://127.0.0.1:4010' failed: 1 (Operation not permitted)
         at galera/src/gcs.hpp:param_set():206
2014-04-30 10:04:34 13562 [ERROR] WSREP: Set options returned 7
2014-04-30 10:04:34 13562 [Note] WSREP: refresh_provider_options: gmcast.listen_addr=tcp://127.0.0.1:4010

The problem is that, without ability to set listen_addr before it
actually listens, it ends up listening on default addr:port.

wsrep_provider_options - http://paste.wnohang.net/5368df

@Raghu

thx for reporting this problem(or bug). And I think the main reason is that bad design of "process of updating provider".

I'll give some thought about the process.

@Raghu

galera provider has three types of options
1. only static (should be set before provider is loaded, can not be changed in runtime) like gmcast.listen_addr, gcache.dir and repl.commit_order (as you specified in https://bugs.launchpad.net/codership-mysql/+bug/1208493/comments/13)
2. static/runtime like gcs.fc_limit, pc.ignore_sb
3. only runtime like gmcast.peer_addr, pc.bootstrap

only type 1,2 options will be preserved when provider is reloaded.

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PXC-986