[ovs-dev] [PATCH v3] ovsdb-tool: Add a db consistency check to the ovsdb-tool check-cluster command

[Dumitru Ceara]

On 7/15/20 4:22 PM, Federico Paolinelli wrote:
> 
> 
> On Tue, Jul 14, 2020 at 10:22 AM Dumitru Ceara <dceara at redhat.com
> <mailto:dceara at redhat.com>> wrote:
> 
>     On 7/10/20 10:18 AM, Federico Paolinelli wrote:
>     > There are some occurrences where the database ends up in an
>     inconsistent
>     > state. This happened in ovn-k8s and is described in [0].
>     > Here we are adding a supported way to check that a given db is
>     consistent,
>     > which is less error prone than checking the logs.
>     >
>     > Tested against both a valid db and a corrupted db attached to the
>     > above bug [1].
>     >
>     > [0]: https://bugzilla.redhat.com/show_bug.cgi?id=1837953#c23
>     > [1]: https://bugzilla.redhat.com/attachment.cgi?id=1697595
>     >
>     > Signed-off-by: Federico Paolinelli <fpaoline at redhat.com
>     <mailto:fpaoline at redhat.com>>
>     > Suggested-by: Dumitru Ceara <dceara at redhat.com
>     <mailto:dceara at redhat.com>>
>     > ---
>     >  ovsdb/ovsdb-tool.c | 22 ++++++++++++++++++++++
>     >  1 file changed, 22 insertions(+)
>     >
>     > diff --git a/ovsdb/ovsdb-tool.c b/ovsdb/ovsdb-tool.c
>     > index 91662cab8..016a3ba28 100644
>     > --- a/ovsdb/ovsdb-tool.c
>     > +++ b/ovsdb/ovsdb-tool.c
>     > @@ -1497,6 +1497,28 @@ do_check_cluster(struct ovs_cmdl_context *ctx)
>     >          }
>     >      }
>     >
>     > +    /* Check for db consistency:
>     > +     * The serverid must be in the servers list.
>     > +     */
>     > +
>     > +    for (struct server *s = c.servers; s <
>     &c.servers[c.n_servers]; s++) {
>     > +        struct shash *servers_obj = json_object(s->snap->servers);
>     > +        char *server_id = xasprintf(SID_FMT,
>     SID_ARGS(&s->header.sid));
>     > +        bool found = false;
>     > +        const struct shash_node *node;
>     > +
>     > +        SHASH_FOR_EACH (node, servers_obj) {
>     > +            if (!strncmp(server_id, node->name, SID_LEN)) {
>     > +                found = true;
>     > +            }
>     > +        }
>     > +        if (!found) {
>     > +            ovs_fatal(0, "%s: server %s not found in server list",
>     > +                      s->filename, server_id);
>     > +        }
>     > +        free(server_id);
>     > +    }
>     > +
>     >      /* Clean up. */
>     >
>     >      for (size_t i = 0; i < c.n_servers; i++) {
>     >
> 
>     Looks good to me, thanks!
> 
>     Acked-by: Dumitru Ceara <dceara at redhat.com <mailto:dceara at redhat.com>>
> 
> 
> Question: does it make sense to add a unit test that validates the
> behaviour
> of this new function? And if so, what would be the best place to add it?
> 
> Thanks!
>  

I might be wrong but I don't see an easy way to generate a corrupted
database to run "ovsdb-tool check-cluster" against.

Thanks,
Dumitru