Hi there,
I am new to Hedwig, and have a question about setting up Hedwig with
two regions. I have successfully set up two separate single-region
instances of Hedwig. But I could not get them communicate with each
other.
Here are my configuration:
I have two physical machines (A and B), each hosting three VMs
mimicking a cluster in a region. In each region, the three VMs run
ZooKeeper servers, BookKeeper bookie servers, and Hedwig servers at
the same time.
For "reg1" (machine A), the three VMs's IP are:
X.Y.Z.111
X.Y.Z.112
X.Y.Z.113
I successfully set them up as a single-region Hedwig instance. I could
run "bin/hedwig console", and successfully executed commands including
"show", "sub", "pub", "pubsub", "readtopic", "describe topic" etc.
I did the same for "reg2" (machine B), where the three VMs are:
X.Y.Z.114
X.Y.Z.115
X.Y.Z.116
Again, "reg2" as a single-region Hedwig instance was running well.
Then, I began to setup the across-region communication of the two
Hedwig instances. I shut down the two Hedwig instances, and set the
"regions" option in hw_server.conf of all 6 VMs to
regions=X.Y.Z.111:4080 X.Y.Z.114:4080
All options, other than zk_host, region, and regions, in
hw_server.conf are left as default. After that, I restarted the two
Hedwig instances. I logged into the console of "reg1" and published
some test messages in a topic. But I could not observe the topic or
messages when I logged into console of "reg2". The same is true vice
versa.
It seemed that the two regions can find each other because I observed
that reg1 contains hub(s) from reg2, and vice versa:
[hedwig: (reg1) 24] show hubs
Available Hub Servers:
X.Y.Z.111:4080:9876 : info : [hostname:
"X.Y.Z.111:4080:9876", czxid: 12884902049], load : [numTopics: 0]
X.Y.Z.116:4080:9876 : info : [hostname:
"X.Y.Z.116:4080:9876", czxid: 12884902050], load : [numTopics: 0]
X.Y.Z.112:4080:9876 : info : [hostname:
"X.Y.Z.112:4080:9876", czxid: 12884902051], load : [numTopics: 1]
[hedwig: (reg2) 8] show hubs
Available Hub Servers:
X.Y.Z.116:4080:9876 : info : [hostname:
"X.Y.Z.116:4080:9876", czxid: 34359738415], load : [numTopics: 0]
X.Y.Z.114:4080:9876 : info : [hostname:
"X.Y.Z.114:4080:9876", czxid: 34359738416], load : [numTopics: 0]
X.Y.Z.112:4080:9876 : info : [hostname:
"X.Y.Z.112:4080:9876", czxid: 34359738417], load : [numTopics: 0]
Another thing I observed is that the "sub" command sometimes hung in
this case. But, I did not find any error message in the log file.
Am I doing something wrong? Did I set the "regions" option correctly?
Any help is
deeply appreciated.
Thanks,
Ming
