Add API to trigger snapshot creation manually

Author: yawzhang

conanfile.py

@@ -10,7 +10,7 @@
 
 class HomeObjectConan(ConanFile):
     name = "homeobject"
-    version = "4.0.8"
+    version = "4.0.9"
 
     homepage = "https://github.com/eBay/HomeObject"
     description = "Blob Store built on HomeStore"

src/lib/homestore_backend/hs_homeobject.cpp

@@ -550,4 +550,15 @@ void HSHomeObject::yield_pg_leadership_to_follower(int32_t pg_id) {
     }
 }
 
+void HSHomeObject::trigger_snapshot_creation(int32_t pg_id, int64_t compact_lsn, bool wait_for_commit) {
+    LOGI("Triggering snapshot creation for pg_id={}, compact_lsn={}, wait_for_commit={}", pg_id, compact_lsn,
+         wait_for_commit);
+    auto hs_pg = get_hs_pg(pg_id);
+    if (!hs_pg) {
+        LOGE("Failed to trigger snapshot: PG {} not found", pg_id);
+        return;
+    }
+    hs_pg->trigger_snapshot_creation(compact_lsn, wait_for_commit);
+}
+
 } // namespace homeobject

src/lib/homestore_backend/hs_homeobject.hpp

@@ -54,7 +54,8 @@ class HSHomeObject : public HomeObjectImpl {
     uint32_t _hs_reserved_blks = 0;
 
     /// Overridable Helpers
-    ShardManager::AsyncResult< ShardInfo > _create_shard(pg_id_t, uint64_t size_bytes, std::string meta, trace_id_t tid) override;
+    ShardManager::AsyncResult< ShardInfo > _create_shard(pg_id_t, uint64_t size_bytes, std::string meta,
+                                                         trace_id_t tid) override;
     ShardManager::AsyncResult< ShardInfo > _seal_shard(ShardInfo const&, trace_id_t tid) override;
 
     BlobManager::AsyncResult< blob_id_t > _put_blob(ShardInfo const&, Blob&&, trace_id_t tid) override;
@@ -196,7 +197,7 @@ class HSHomeObject : public HomeObjectImpl {
     };
 
     struct shard_info_superblk : DataHeader {
-        //This version is a common version of DataHeader, each derived struct can have its own version.
+        // This version is a common version of DataHeader, each derived struct can have its own version.
         static constexpr uint8_t shard_sb_version = 0x02;
 
         uint8_t sb_version{shard_sb_version};
@@ -394,6 +395,8 @@ class HSHomeObject : public HomeObjectImpl {
 
         void yield_leadership_to_follower() const;
 
+        void trigger_snapshot_creation(int64_t compact_lsn, bool wait_for_commit) const;
+
         /**
          * Returns all shards
          */
@@ -437,7 +440,7 @@ class HSHomeObject : public HomeObjectImpl {
         uint32_t data_offset;   // Offset of actual data blob stored after the metadata
         uint32_t user_key_size; // Actual size of the user key.
         uint8_t user_key[max_user_key_length + 1]{};
-        uint8_t padding[2956]{};  // data_block_size is 4K, so total size of BlobHeader is 4096 bytes
+        uint8_t padding[2956]{}; // data_block_size is 4K, so total size of BlobHeader is 4096 bytes
 
         std::optional< std::string > get_user_key() const {
             if (user_key_size > max_user_key_length) { return std::nullopt; }
@@ -969,6 +972,22 @@ class HSHomeObject : public HomeObjectImpl {
      */
     void yield_pg_leadership_to_follower(int32_t pg_id = 1);
 
+    /**
+     * @brief Manually trigger a snapshot creation.
+     * @param compact_lsn Expected compact up to LSN. Default is -1, meaning it depends directly on the current HS
+     * status.
+     * @param wait_for_commit Wait committed lsn reaches compact_lsn. Default is true, false means the snapshot will be
+     * triggered based on its latest committed lsn and the log compaction depends on min(snapshot_lsn, compact_lsn)
+     *
+     * Recommendation:
+     * - Please keep wait_for_commit=true to make sure the compact_lsn <= committed_lsn when snapshot is created. If you
+     * just want to trigger a snapshot manually or want to update the compact_lsn (already less than committed_lsn) for
+     * log compaction, you can set wait_for_commit=false.
+     * - wait_for_commit=true might cause the caller blocked for a while until the committed_lsn reaches compact_lsn.
+     * Please keep in mind and take action if this function costs too long.
+     */
+    void trigger_snapshot_creation(int32_t pg_id, int64_t compact_lsn, bool wait_for_commit);
+
     // Blob manager related.
     void on_blob_message_rollback(int64_t lsn, sisl::blob const& header, sisl::blob const& key,
                                   cintrusive< homestore::repl_req_ctx >& hs_ctx);

src/lib/homestore_backend/hs_http_manager.cpp

@@ -37,6 +37,8 @@ HttpManager::HttpManager(HSHomeObject& ho) : ho_(ho) {
          Pistache::Rest::Routes::bind(&HttpManager::reconcile_leader, this)},
         {Pistache::Http::Method::Post, "/api/v1/yield_leadership_to_follower",
          Pistache::Rest::Routes::bind(&HttpManager::yield_leadership_to_follower, this)},
+        {Pistache::Http::Method::Post, "/api/v1/trigger_snapshot_creation",
+         Pistache::Rest::Routes::bind(&HttpManager::trigger_snapshot_creation, this)},
 #ifdef _PRERELEASE
         {Pistache::Http::Method::Post, "/api/v1/crashSystem",
          Pistache::Rest::Routes::bind(&HttpManager::crash_system, this)},
@@ -91,6 +93,36 @@ void HttpManager::yield_leadership_to_follower(const Pistache::Rest::Request& re
     response.send(Pistache::Http::Code::Ok, "Yield leadership request submitted");
 }
 
+void HttpManager::trigger_snapshot_creation(const Pistache::Rest::Request& request,
+                                            Pistache::Http::ResponseWriter response) {
+    // Extract and validate pg_id parameter (required)
+    const auto pg_id_param = request.query().get("pg_id");
+    if (!pg_id_param) {
+        response.send(Pistache::Http::Code::Bad_Request, "pg_id is required");
+        return;
+    }
+    const int32_t pg_id = std::stoi(pg_id_param.value());
+
+    // Extract compact_lsn parameter (optional, default: -1 means use current HS status)
+    const auto compact_lsn_param = request.query().get("compact_lsn");
+    const int64_t compact_lsn = std::stoll(compact_lsn_param.value_or("-1"));
+
+    // Extract wait_for_commit parameter (optional, default: true)
+    const auto wait_for_commit_param = request.query().get("wait_for_commit");
+    std::string wait_for_commit_mode = wait_for_commit_param.value_or("true");
+    if (wait_for_commit_mode != "true" && wait_for_commit_mode != "false") {
+        response.send(Pistache::Http::Code::Bad_Request, "wait_for_commit must be 'true' or 'false'");
+        return;
+    }
+    bool wait_for_commit = (wait_for_commit_mode == "true");
+
+    LOGINFO("Received snapshot creation request for pg_id={}, compact_lsn={}, wait_for_commit={}", pg_id, compact_lsn,
+            wait_for_commit);
+
+    ho_.trigger_snapshot_creation(pg_id, compact_lsn, wait_for_commit);
+    response.send(Pistache::Http::Code::Ok, "Snapshot creation request submitted");
+}
+
 void HttpManager::get_pg(const Pistache::Rest::Request& request, Pistache::Http::ResponseWriter response) {
     auto pg_str = request.query().get("pg_id");
     if (!pg_str) {

src/lib/homestore_backend/hs_http_manager.hpp

@@ -28,6 +28,7 @@ class HttpManager {
     void get_malloc_stats(const Pistache::Rest::Request& request, Pistache::Http::ResponseWriter response);
     void reconcile_leader(const Pistache::Rest::Request& request, Pistache::Http::ResponseWriter response);
     void yield_leadership_to_follower(const Pistache::Rest::Request& request, Pistache::Http::ResponseWriter response);
+    void trigger_snapshot_creation(const Pistache::Rest::Request& request, Pistache::Http::ResponseWriter response);
     void get_pg(const Pistache::Rest::Request& request, Pistache::Http::ResponseWriter response);
     void get_pg_chunks(const Pistache::Rest::Request& request, Pistache::Http::ResponseWriter response);
     void dump_chunk(const Pistache::Rest::Request& request, Pistache::Http::ResponseWriter response);

src/lib/homestore_backend/hs_pg_manager.cpp

@@ -797,6 +797,10 @@ void HSHomeObject::HS_PG::yield_leadership_to_follower() const {
     repl_dev_->yield_leadership(false /*immediate_yield*/, candidate_leader_id);
 }
 
+void HSHomeObject::HS_PG::trigger_snapshot_creation(int64_t compact_lsn, bool wait_for_commit) const {
+    repl_dev_->trigger_snapshot_creation(compact_lsn, wait_for_commit);
+}
+
 std::vector< Shard > HSHomeObject::HS_PG::get_chunk_shards(chunk_num_t v_chunk_id) const {
     std::vector< Shard > ret;
     for (auto const& s : shards_) {