On 6/27/25 2:09 PM, Ilya Maximets wrote: > Currently, there is no convenient way to know what are the constraints > for a particular column in the server's schema in C IDL. This is > a problem, because clients may want to know how many elements are > allowed in a certain column. For example, we recently increased the > allowed number of prefixes configured in the Flow_Table table in OVS, > but the client (ovn-controller) has no good way to know how many > prefixes are actually supported in the schema of the currently running > ovsdb-server. The IDL's code is generated from one schema version, > while the actual server may be using newer or older one. If the > client specifies too many prefixes, the transaction will fail, and > there is also no good way to tell from the ovn-controller why exactly > transaction failed. > > Currently used solution is to create another database connection just > to intercept schema changes and parse the schema JSON manually inside > the ovn-controller: > > https://github.com/ovn-org/ovn/commit/89e43f7528b067b1bc9f6c5fd67857b39ebc518d > > While this approach works, it's not a clean solution. We have the > server's schema on the CS level and we can provide the types to the > application via IDL functions. This will allow ovn-controller to > just use ovsrec_flow_table_prefixes_server_type(idl)->n_max instead > of all the awkward schema parsing. > > Python IDL is more dynamic and has a different way of connecting > where the user first obtains the schema and then initializes IDL > with that schema. The parsed schema object with all the types is > also available through the get_idl_schema() method. So, it is > already possible to check the types there. > > Signed-off-by: Ilya Maximets <i.maxim...@ovn.org> > ---
Hi Ilya, > NEWS | 4 +++ > lib/ovsdb-cs.c | 64 +++++++++++++++++++++++++--------- > lib/ovsdb-idl-provider.h | 3 +- > lib/ovsdb-idl.c | 74 ++++++++++++++++++++++++++++++++++------ > lib/ovsdb-idl.h | 3 ++ > ovsdb/ovsdb-idlc.in | 12 +++++++ > tests/ovsdb-idl.at | 10 +++--- > tests/test-ovsdb.c | 33 +++++++++++++----- > 8 files changed, 162 insertions(+), 41 deletions(-) > > diff --git a/NEWS b/NEWS > index d7231fabc..7f2d3462a 100644 > --- a/NEWS > +++ b/NEWS > @@ -8,6 +8,10 @@ Post-v3.5.0 > * New debug appctl command 'dpdk/get-memzone-stats'. > * Removed upper limit for the number of rx/tx descriptors > (n_r/txq_desc). > * OVS validated with DPDK 24.11.2. > + - OVSDB-IDL: > + * New functions <db>_<table>_<column>_server_type() that allow checking > + the server-side type of a particular column. Can be used for checking > + type constraints when the server schema is older or newer than > client's. Nit (but I'm no native speaker so take this with a grain of salt): s/than client's/than that of the client/. Otherwise the rest looks good to me, thanks for the nice addition! Acked-by: Dumitru Ceara <dce...@redhat.com> Regards, Dumitru _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
