mongo/jstests/libs/shard_transition_util.js

/**
 * Utilities for testing shard and config server transition behaviors
 */
import {FeatureFlagUtil} from "jstests/libs/feature_flag_util.js";

export const ShardTransitionUtil = (function () {
    function isConfigServerTransitionEnabledIgnoringFCV(st) {
        return FeatureFlagUtil.isEnabled(
            st.configRS.getPrimary(),
            "TransitionToCatalogShard",
            undefined /* user */,
            true /* ignoreFCV */,
        );
    }

    function transitionToDedicatedConfigServer(st, timeout) {
        if (timeout == undefined) {
            timeout = 10 * 60 * 1000; // 10 minutes
        }

        // TODO (SERVER-97816): remove multiversion check and assume removeShard is idempotent.
        const isMultiversion = Boolean(jsTest.options().useRandomBinVersionsWithinReplicaSet);
        assert.soon(
            function () {
                const res = st.s.adminCommand({transitionToDedicatedConfigServer: 1});
                if (isMultiversion && !res.ok && res.code === ErrorCodes.ShardNotFound) {
                    // If the config server primary steps down right after removing the config.shards
                    // doc for the shard but before responding with "state": "completed", the mongos
                    // would retry the _configsvrTransitionToDedicatedConfigServer command against the
                    // new config server primary, which would not find the removed shard in its
                    // ShardRegistry if it has done a ShardRegistry reload after the config.shards doc
                    // for the shard was removed. This would cause the command to fail with
                    // ShardNotFound.
                    return true;
                }
                assert.commandWorked(res);
                return res.state == "completed";
            },
            "failed to transition to dedicated config server within " + timeout + "ms",
            timeout,
        );
    }

    function waitForRangeDeletions(conn) {
        assert.soon(() => {
            const rangeDeletions = conn.getCollection("config.rangeDeletions").find().toArray();
            if (rangeDeletions.length) {
                jsTest.log.info("Waiting for range deletions to complete", {rangeDeletions});
                sleep(100);
                return false;
            }
            return true;
        });
    }

    function retryOnShardTransitionErrors(func) {
        while (true) {
            try {
                func();
                return;
            } catch (e) {
                if (e.code === ErrorCodes.ShardNotFound) {
                    jsTest.log.info("Ignoring error with transitioning shard, retrying", {error: e});
                    continue;
                }

                throw e;
            }
        }
    }

    return {
        isConfigServerTransitionEnabledIgnoringFCV,
        transitionToDedicatedConfigServer,
        waitForRangeDeletions,
        retryOnShardTransitionErrors,
    };
})();