private void defineIndexRule(String modelName,
                                 IndexRule indexRule,
                                 BanyanDBClient client) throws BanyanDBException {
        if (checkIndexRuleProcessed(modelName, indexRule)) {
            return;
        }
        try {
            client.define(indexRule);
            log.info("new IndexRule created: {}", indexRule.getMetadata().getName());
        } catch (BanyanDBException ex) {
            if (ex.getStatus().equals(Status.Code.ALREADY_EXISTS)) {
                log.info("IndexRule {} already created by another OAP node", indexRule.getMetadata().getName());
            } else {
                throw ex;
            }
        }
    }
Define the index rule if not exist and no conflict.
oap-server/server-storage-plugin/storage-banyandb-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/banyandb/BanyanDBIndexInstaller.java