[Pacemaker] Serious issue with booth for site failover

Fri Jan 18 13:24:57 EST 2013

Hi,
   learning about the paxos protocol, I realize the problem is not with 
the arbitrator, but the surviving node.  Here its debug output:

booth-site[2552]: 2013/01/18_11:26:36 debug: preposer prepare ...
booth-site[2552]: 2013/01/18_11:26:36 debug: enter lease_prepare
booth-site[2552]: 2013/01/18_11:26:36 debug: exit lease_prepare
booth-site[2552]: 2013/01/18_11:26:36 debug: acceptor promise ...
booth-site[2552]: 2013/01/18_11:26:36 debug: enter lease_promise
booth-site[2552]: 2013/01/18_11:26:36 debug: enter start_lease_promise
booth-site[2552]: 2013/01/18_11:26:36 debug: has not been leased
booth-site[2552]: 2013/01/18_11:26:36 debug: exit start_lease_promise
booth-site[2552]: 2013/01/18_11:26:36 debug: exit lease_promise
booth-site[2552]: 2013/01/18_11:26:36 debug: proposer propose ...
booth-site[2552]: 2013/01/18_11:26:36 debug: enter lease_is_prepared
booth-site[2552]: 2013/01/18_11:26:36 debug: enter start_lease_is_prepared
booth-site[2552]: 2013/01/18_11:26:36 debug: not leased
booth-site[2552]: 2013/01/18_11:26:36 debug: exit lease_is_prepared
booth-site[2552]: 2013/01/18_11:26:48 debug: lease_retry ...
booth-site[2552]: 2013/01/18_11:26:48 debug: preposer prepare ...
booth-site[2552]: 2013/01/18_11:26:48 debug: enter lease_prepare
booth-site[2552]: 2013/01/18_11:26:48 debug: exit lease_prepare
booth-site[2552]: 2013/01/18_11:26:48 debug: acceptor promise ...
booth-site[2552]: 2013/01/18_11:26:48 debug: enter lease_promise
booth-site[2552]: 2013/01/18_11:26:48 debug: enter start_lease_promise
booth-site[2552]: 2013/01/18_11:26:48 debug: has not been leased
booth-site[2552]: 2013/01/18_11:26:48 debug: exit start_lease_promise
booth-site[2552]: 2013/01/18_11:26:48 debug: exit lease_promise
booth-site[2552]: 2013/01/18_11:26:48 debug: proposer propose ...
booth-site[2552]: 2013/01/18_11:26:48 debug: enter lease_is_prepared
booth-site[2552]: 2013/01/18_11:26:48 debug: enter start_lease_is_prepared
booth-site[2552]: 2013/01/18_11:26:48 debug: not leased
booth-site[2552]: 2013/01/18_11:26:48 debug: exit lease_is_prepared

Also, I don't know if it makes a difference but the test VMs are 32 bits.

Regards,

Yves

Le 2013-01-18 11:49, Yves Trudeau a écrit :
> Hi,
>     working on a geo-redundant setup, I uncovered a problem with booth.
>   In order to simplify, I did an experiment with only booth, no
> pacemaker.  The behavior is the same with pacemaker.
>
> Version used
> ------------
>
> git log
> commit 55ab027233407fd44850f0c4905b085205d55f64
> Author: Xia Li <xli at suse.com>
> Date:   Thu Jan 10 13:48:20 2013 +0800
>
> Config file
> -----------
>
> transport="UDP"
> port="6666"
> arbitrator="10.3.3.1"
> site="10.3.1.10"
> site="10.3.2.10"
> ticket="ticketMaster;120"
>
> *same on all nodes.
>
> Invocations
> -----------
>
> root at 10.3.3.1:~# /usr/sbin/boothd arbitrator -D
>
> root at 10.3.1.10:~# /usr/sbin/boothd site -D
>
> root at 10.3.2.10:~# /usr/sbin/boothd site -D
>
> Initial state
> -------------
>
> root at 10.3.3.1:~# booth client list
> ticket: ticketMaster, owner: None, expires: INF
>
> * same on all 3 nodes
>
> Granting the ticket
> -------------------
>
> root at 10.3.3.1:~# booth client grant -t ticketMaster -s 10.3.2.10
> cluster[25103]: 2013/01/18_11:16:35 info: grant command sent, result
> will be returned asynchronously, you can get the result from the log files
>
> Status after grant
> ------------------
>
> root at 10.3.3.1:~# booth client list
> ticket: ticketMaster, owner: 10.3.2.10, expires: 2013/01/18 11:20:11
>
> * same on all 3 nodes, so far so good
>
> Simulation a network outage on 10.3.2.10
> ----------------------------------------
>
> root at 10.3.2.10:~# iptables -I INPUT -s 10.3.1.0/24 -j DROP; iptables -I
> INPUT -s 10.3.3.0/24 -j DROP; iptables -I OUTPUT -d 10.3.1.0/24 -j DROP;
> iptables -I OUTPUT -d 10.3.2.0/24 -j DROP
>
> after the outage, here the last lines of the arbitrator:
>
> booth-arbitrator[25055]: 2013/01/18_11:26:47 debug: exit
> start_lease_promise
> booth-arbitrator[25055]: 2013/01/18_11:26:47 debug: exit lease_promise
> booth-arbitrator[25055]: 2013/01/18_11:26:47 debug: acceptor promise ...
> booth-arbitrator[25055]: 2013/01/18_11:26:47 debug: ballot number: 4,
> highest promised: 5
> booth-arbitrator[25055]: 2013/01/18_11:28:11 debug: lease expires ...
> booth-arbitrator[25055]: 2013/01/18_11:28:11 info: command: 'crm_ticket
> -t ticketMaster -S owner -v -1' was executed
> Error signing on to the CIB service: connection failed
> booth-arbitrator[25055]: 2013/01/18_11:28:11 info: command: 'crm_ticket
> -t ticketMaster -S expires -v 0' was executed
> Error signing on to the CIB service: connection failed
> booth-arbitrator[25055]: 2013/01/18_11:28:11 info: command: 'crm_ticket
> -t ticketMaster -S ballot -v 2' was executed
> Error signing on to the CIB service: connection failed
> booth-arbitrator[25055]: 2013/01/18_11:28:11 info: command: 'crm_ticket
> -t ticketMaster -r --force' was executed
> Error signing on to the CIB service: connection failed
> booth-arbitrator[25055]: 2013/01/18_11:28:11 debug: only proposer can do
> this
> booth-arbitrator[25055]: 2013/01/18_11:28:23 debug: lease_retry ...
> booth-arbitrator[25055]: 2013/01/18_11:28:23 debug: only proposer can do
> this
>
> and of course:
>
> root at 10.3.1.10:~# booth client list
> ticket: ticketMaster, owner: None, expires: INF
>
> The debug message "only proposer can do this" comes from the
> paxos_round_request functions in paxos.c with the condition:
>
> if (!(pi->ps->role[myid] & PROPOSER)) {
>      log_debug("only proposer can do this");
>      return -EOPNOTSUPP;
> }
>
> So my pick is the the PROPOSER bit is not set correctly in the structure
> in the lease_expires and lease_retry functions.  I am not very familiar
> with that code base but I'll try to figure out the issue and submit a
> patch on git hub.
>
> Regards,
>
> Yves
>
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