Summary

When processing flex-counter SET events, some VIDs in the event payload may no longer translate to RIDs (for example after a port was removed or split). When translation fails for one or more VIDs in a SET event, the system can end up with stale entries in the flex-counter database and in the counter manager, and bulk counter operations may be invoked with mismatched or invalid inputs.

Missing VID cleanup in the code

File: syncd/Syncd.cpp — code snippet where invalid-VID cleanup is missing

if (fromAsicChannel && op == SET_COMMAND && (!vidStringVector.empty()))
{
    std::vector<sai_object_id_t> vids;
    std::vector<sai_object_id_t> rids;
    std::vector<std::string> keys;
    ...
    for (auto &strVid: vidStringVector)
    {
        sai_object_id_t vid, rid;
        sai_deserialize_object_id(strVid, vid);
        vids.emplace_back(vid);

        if (!m_translator->tryTranslateVidToRid(vid, rid))
        {
            SWSS_LOG_ERROR("port VID %s, was not found (probably port was removed/splitted)",
                           sai_serialize_object_id(vid).c_str());
            continue;
        }

        rids.emplace_back(rid);
        keys.emplace_back(groupName + ":" + strVid);
    }

    m_manager->bulkAddCounter(vids, rids, groupName, values);

    for (auto &singleKey: keys)
    {
        m_flexCounterTable->set(singleKey, values);
    }

    if (fromAsicChannel)
    {
        sendApiResponse(SAI_COMMON_API_SET, SAI_STATUS_SUCCESS);
    }
}

This is the section in the original code where invalid VIDs were skipped (logged) but not removed from the FLEX_COUNTER_TABLE or from the counter manager before calling bulkAddCounter.

Observed symptoms

• Stale flex-counter keys remain in the DB (groupName:VID) for VIDs that no longer exist or translate.
• The counter manager retains entries for removed ports, leading to resource/state leak.
• Bulk counter operations may be called with mismatched inputs (e.g., VIDs present that do not have corresponding valid RIDs), potentially causing incorrect bookkeeping or errors further downstream.
• Log messages (from flex-counter processing) indicating failed translation or missing port RIDs when events arrive referencing removed/split ports.