chore: add TODO breadcrumbs for the Helm chart's server workarounds

hugegraph-pd/hg-pd-core/src/main/java/org/apache/hugegraph/pd/StoreNodeService.java

@@ -158,6 +158,12 @@ public Metapb.Store register(Metapb.Store store) throws PDException {
         }
 
         // offline or up, or in the initial activation list, go live automatically
+        // TODO: do not mark a re-registering Store Up before it has restored its partition engines
+        // (HgStoreEngine.restoreLocalPartitionEngine); report a restoring state, or expose
+        // restore-complete per shard group, so a rolling restart can wait on it. The Helm chart
+        // (helm/hugegraph) keeps Store rollouts on OnDelete with a manual /v1/shardGroups barrier
+        // between Pod deletions; retire that procedure once PD reports restoration.
+        // https://github.com/apache/hugegraph/issues/3229
         Metapb.StoreState storeState = lastStore.getState();
         if (storeState == Metapb.StoreState.Offline || storeState == Metapb.StoreState.Up
             || inInitialStoreList(store)) {

hugegraph-pd/hg-pd-core/src/main/java/org/apache/hugegraph/pd/raft/RaftStateMachine.java

@@ -167,6 +167,11 @@ public void onLeaderStart(final long term) {
     @Override
     public void onLeaderStop(final Status status) {
         this.leaderTerm.set(-1);
+        // TODO: keep STATE_ERROR set by onError instead of overwriting it with STATE_FOLLOWER, so
+        // the probe view (and /v1/health, see StoreAPI.checkHealthy) can report a PD that stepped
+        // down for good after a snapshot failure. The Helm chart (helm/hugegraph) works around the
+        // missing signal with pd.livenessPath on /v1/ready for a single PD.
+        // https://github.com/apache/hugegraph/issues/3222
         this.probeView = new ProbeView(State.STATE_FOLLOWER, false);
         super.onLeaderStop(status);
         log.info("Raft  lost leader ");

hugegraph-pd/hg-pd-core/src/main/java/org/apache/hugegraph/pd/store/HgKVStoreImpl.java

@@ -78,6 +78,11 @@ public void init(PDConfig config) {
             }
             openRocksDB(dbPath);
         } catch (PDException e) {
+            // TODO: retry the open and then fail PD startup instead of logging: a held RocksDB LOCK
+            // leaves this PD running uninitialized (/v1/ready answers 503 STATE_UNINITIALIZED
+            // while /v1/health answers 200), and with several PDs nothing restarts it. The Helm
+            // chart (helm/hugegraph) documents this as a limitation; drop that entry once fixed.
+            // https://github.com/apache/hugegraph/issues/3226
             log.error("Failed to open data file,{}", e);
         } finally {
             writeLock.unlock();

hugegraph-pd/hg-pd-service/src/main/java/org/apache/hugegraph/pd/rest/StoreAPI.java

@@ -395,6 +395,12 @@ class StoreStatistics {
      * @return Returns a string indicating the service's health status. Typically, an empty
      * string indicates the service is healthy.
      */
+    // TODO: answer non-200 when the raft state machine is in STATE_ERROR (a failed snapshot) or
+    // the KV store never opened (a held RocksDB LOCK): both leave this PD unable to recover while
+    // /health stays 200 forever. The Helm chart (helm/hugegraph) derives a single PD's startup
+    // and liveness probes to /v1/ready for this reason; drop that derivation once this reports it.
+    // https://github.com/apache/hugegraph/issues/3222
+    // https://github.com/apache/hugegraph/issues/3226
     @GetMapping(value = "/health", produces = MediaType.TEXT_PLAIN_VALUE)
     public Serializable checkHealthy() {
         return "";

hugegraph-pd/hg-pd-service/src/main/java/org/apache/hugegraph/pd/rest/TaskAPI.java

@@ -89,6 +89,12 @@ public String splitPartitions() {
         }
     }
 
+    // TODO: make the task routes tell a real run from a no-op and a follower answer (a follower
+    // returns an empty success without doing anything), and return a body that names what was
+    // scheduled. Part 1 (#3233) replaced the bare 500 with a refusal body; this is part 2. The
+    // Helm chart (helm/hugegraph) documents the leader-first sequence and the 180 s spacing in its
+    // README until then.
+    // https://github.com/apache/hugegraph/issues/3231
     @GetMapping(value = "/balanceLeaders", produces = MediaType.APPLICATION_JSON_VALUE)
     @ResponseBody
     public String balanceLeaders() {

hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/api/filter/AuthenticationFilter.java

@@ -75,6 +75,10 @@ public class AuthenticationFilter implements ContainerRequestFilter, ContainerRe
     private static final Logger LOG = Log.logger(AuthenticationFilter.class);
 
     private static final AntPathMatcher MATCHER = new AntPathMatcher();
+    // TODO: add the unauthenticated /readiness probe (#3221) here once it lands. The Helm chart
+    // (helm/hugegraph) defaults server.readinessPath to /versions, which stays 200 with zero
+    // Stores, and offers /readiness as an opt-in; flip that default when this set grows.
+    // https://github.com/apache/hugegraph/issues/3212
     private static final Set<String> FIXED_WHITE_API_SET = ImmutableSet.of(
             "versions",
             "openapi.json"
@@ -180,6 +184,11 @@ protected User authenticate(ContainerRequestContext context) {
 
         if (auth.startsWith(BASIC_AUTH_PREFIX)) {
             auth = auth.substring(BASIC_AUTH_PREFIX.length());
+            // TODO: decode the Basic credential as UTF-8 and split it on the first colon only.
+            // Decoding as ASCII and splitting on every colon makes a non-ASCII password answer
+            // 401 and a password containing ':' answer 400, although both were accepted at
+            // account creation. The Helm chart (helm/hugegraph) refuses such admin passwords in
+            // its schema and Server wrapper; drop that guard once this is fixed.
             auth = new String(DatatypeConverter.parseBase64Binary(auth), Charsets.ASCII_CHARSET);
             String[] values = auth.split(":");
             if (values.length != 2) {

hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/config/ServerOptions.java

@@ -480,6 +480,11 @@ public class ServerOptions extends OptionHolder {
                     ""
             );
 
+    // TODO: accept the initial admin password from the environment (or document the properties
+    // contract): read through PropertiesConfiguration, the value is trimmed, backslash-unescaped
+    // and decoded as ISO-8859-1, so the stored password can differ from what the operator set.
+    // The Helm chart (helm/hugegraph) refuses padded, backslash or non-ASCII admin passwords in
+    // its schema and Server wrapper; relax that guard once the credential bypasses the file.
     public static final ConfigOption<String> ADMIN_PA =
             new ConfigOption<>(
                     "auth.admin_pa",

hugegraph-server/hugegraph-api/src/main/java/org/apache/hugegraph/core/GraphManager.java

@@ -1820,6 +1820,13 @@ private String defaultSpaceGraphName(String graphName) {
     }
 
     private void loadGraph(String name, String graphConfPath) {
+        // TODO: offer a loaded graph to Gremlin Server (notify GRAPH_CREATE, as the create paths
+        // do) or fail startup when its static Gremlin instantiation failed. Today a Server whose
+        // first open failed against a PD member mid-restart serves REST and passes readiness
+        // while every Gremlin call on it fails for the life of the process. The Helm chart
+        // (helm/hugegraph) detects this with a per-Pod Gremlin query in `helm test` and documents
+        // the manual Pod deletion; retire both once this is fixed.
+        // https://github.com/apache/hugegraph/issues/3228
         HugeConfig config = new HugeConfig(graphConfPath);
 
         // Transfer `raft.group_peers` from server config to graph config

hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/auth/StandardAuthManager.java

@@ -159,6 +159,10 @@ private void invalidateUserCache() {
     }
 
     private void invalidatePasswordCache(Id id) {
+        // TODO: invalidate the password and token caches on every Server replica, not only on the
+        // one that handled updateUser; with a shared PD catalog the other replicas accept the old
+        // password until auth.cache_expire elapses. The Helm chart (helm/hugegraph) documents the
+        // per-replica expiry as a limitation of admin password rotation; drop it once fixed.
         this.pwdCache.invalidate(id);
         // Clear all tokenCache because can't get userId in it
         this.tokenCache.clear();

hugegraph-server/hugegraph-dist/docker/docker-entrypoint.sh

@@ -146,6 +146,10 @@ if [[ -n "${PASSWORD:-}" && -z "${HG_SERVER_AUTH_TOKEN_SECRET:-}" ]]; then
 fi
 
 # ── Map env → properties file ─────────────────────────────────────────
+# TODO: map server.urls_to_pd, server.deploy_in_k8s and auth.admin_pa from the environment here.
+# Without them the Helm chart (helm/hugegraph) rewrites rest-server.properties in a wrapper before
+# exec'ing this script, which is why it refuses readOnlyRootFilesystem for Server; drop that
+# wrapper once these keys have an env mapping.
 [[ -n "${HG_SERVER_BACKEND:-}"  ]] && set_prop "backend"  "${HG_SERVER_BACKEND}"  "${GRAPH_CONF}"
 [[ -n "${HG_SERVER_PD_PEERS:-}" ]] && set_prop "pd.peers" "${HG_SERVER_PD_PEERS}" "${GRAPH_CONF}"
 [[ -n "${HG_SERVER_USE_PD:-}" ]] && \

hugegraph-store/hg-store-core/src/main/java/org/apache/hugegraph/store/HgStoreEngine.java

@@ -260,6 +260,11 @@ public void stateChanged(Store store, Metapb.StoreState oldState, Metapb.StoreSt
      * 1. Need to check the partition saved this time, delete the invalid partitions.
      */
     public void restoreLocalPartitionEngine() {
+        // TODO: surface the outcome of this restore (a per-group ready signal, or a failed state
+        // reported to PD) instead of logging only; a Store is marked Up before this runs and a
+        // failed restore leaves it Up with missing shard groups. Paired with the TODO in
+        // StoreNodeService; the Helm chart's manual Store roll barrier depends on it.
+        // https://github.com/apache/hugegraph/issues/3229
         try {
             if (!options.isFakePD()) {  // FakePD mode does not require synchronization
                 partitionManager.syncPartitionsFromPD(partition -> {

hugegraph-store/hg-store-dist/src/assembly/static/conf/application-pd.yml

@@ -27,6 +27,10 @@ management:
 
 rocksdb:
   # rocksdb total memory usage, force flush to disk when reaching this value
+  # TODO: make this overridable from the environment, or default it to 0 so AppConfig falls back
+  # to the JVM max heap: pinned at 32 GB, a Store in a container with a smaller memory limit is
+  # OOM-killed by native caches outside the heap. The Helm chart (helm/hugegraph) can only
+  # document the ceiling and size its cluster preset around it until then.
   total_memory_size: 32000000000
   # memtable size used by rocksdb
   write_buffer_size: 32000000