[Question] metadataServiceUri with multiple zk servers

[yongzhang]

Hi,

From the documents, I can see zkServers parameter has been deprecated in favor of using metadataServiceUri, but I can't see any example to define metadataServiceUri with multiple zk servers? Please help, thanks.

zk+hierarchical://localhost:2181/ledgers

Is it something like this?

zk+hierarchical://server1:2181/ledgers,zk+hierarchical://server2:2181/ledgers,zk+hierarchical://server3:2181/ledgers

[eolivelli]

No, it should be like
zk://server2:port,server2:port/ledgers

[eolivelli]

@hiscal2015 can you try with my suggested URI?

[yongzhang]

@eolivelli Sorry for delay, looks format zk://server1:port,server2:port,server3:port/ledgers does not work,

I tried with zk+hierarchical://server1:2181/ledgers,zk+hierarchical://server2:2181/ledgers,zk+hierarchical://server3:2181/ledgers, it works fine, can you have a double check? Thanks a lot.

[eolivelli]

This sounds to me as a big problem.
I have to performs trials and reproduce your case.
Are you using that config both on bookie and client?

[yongzhang]

Looks like the setting is only available on bookie, client only needs webservice and broker url.

[eolivelli]

@hiscal2015 metadataServiceUri is available on client as well.
Are you using directly a client or another application ?

[sijie]

@hiscal2015 hmm, I think ',' can not be used in a java URI. URI will take characters before ','. That might example why you see zk://server1:port,server2:port,server3:port/ledgers doesn't work and zk+hierarchical://server1:2181/ledgers,zk+hierarchical://server2:2181/ledgers,zk+hierarchical://server3:2181/ledgers works.

Can you try zk://server1:port;server2:port;server3:port/ledgers?

Looks like the setting is only available on bookie, client only needs webservice and broker url.

from pulsar's perspective, it is a setting for broker and bookies.

[eolivelli]

In fact the code which translates from the legacy zkServer to the new model is

bookkeeper/bookkeeper-server/src/main/java/org/apache/bookkeeper/conf/AbstractConfiguration.java

Line 238 in d9444ba

if (null != zkServers) {

and it simply concatenates:

• metadata protocol
• list of zk servers
• ledgers path

[sijie]

@eolivelli I think the question how current code extracts zk servers from metadata service uri. I know dlog uri handles ';' and converts it to ','. but I am not very sure about the new metadata service uri, have to look more into this.

[sijie]

@hiscal2015 any luck with zk://server1:port;server2:port;server3:port/ledgers?

[yongzhang]

@sijie My cluster was destroyed days ago, I'll get it back to you once cluster coming back again.

[sijie]

@hiscal2015 cool thank you

[sijie]

@hiscal2015 I am closing this issue since the question is answered. If you still see the issue, please reopen it.

[yongzhang]

@sijie @eolivelli

Today I changed metadataServiceUri to zk://server1:port;server2:port;server3:port/ledgers and see below logs:

Nov 28 15:08:46 bookkeeper[1105]: 2018-11-28 15:08:46,217 - INFO  - [main:ZKMetadataDriverBase@186] - Initialize zookeeper metadata driver at metadata service uri zk+hierarchical://10.10.100.17:2181;10.10.100.31:2181;10.10.100.27:2181/ledgers : zkServers = 10.10.100.17:2181,10.10.100.31:2181,10.10.100.27:2181, ledgersRootPath = /ledgers.

Is that means this is succeed?

[sijie]

@hiscal2015 yes that succeed

[ghost]

Hi I can't get this to work..
I tried with different values, yet all i get is
14:13:07.675 [main] INFO org.apache.bookkeeper.meta.zk.ZKMetadataDriverBase - Initialize zookeeper metadata driver at metadata service uri zk+null://localhost:2181/ledgers : zkServers = lo Caused by: org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss calhost:2181, ledgersRootPath = /ledgers.

here is how my bookie.conf looks like. can you please help me figure out the format..

#############################################################################
## ZooKeeper parameters
#############################################################################

# A list of one of more servers on which Zookeeper is running.
# The server list can be comma separated values, for example:
#zkServers=zk-0:2181,zk-1:2181,zk-2:2181
#zkServers=10.42.3.12:2181,10.42.4.8:2181,10.42.5.6:2181
#zkServers=localhost:2181
#metadataServiceUri=zk+hierarchical://zk-0:2181/ledgers,zk+hierarchical://zk-1:2181/ledgers,zk+hierarchical://zk-2:2181/ledgers
metadataServiceUri=zk+hierarchical://10.42.3.12:2181/ledgers,zk+hierarchical://10.42.4.8:2181/ledgers,zk+hierarchical://10.42.5.6:2181/ledgers