Issue 90: wire in discover_svc_id to HomeBlk's Superblk and its recovery

conanfile.py

@@ -9,7 +9,7 @@
 
 class HomeBlocksConan(ConanFile):
     name = "homeblocks"
-    version = "0.0.15"
+    version = "1.0.15"
     homepage = "https://github.com/eBay/HomeBlocks"
     description = "Block Store built on HomeStore"
     topics = ("ebay")

src/include/homeblks/home_blks.hpp

@@ -59,7 +59,7 @@ class HomeBlocksApplication {
     virtual uint64_t app_mem_size() const = 0;
 
     // Callback made after determining if a SvcId exists or not during initialization, will consume response
-    virtual peer_id_t discover_svcid(std::optional< peer_id_t > const& found) const = 0;
+    virtual std::optional< peer_id_t > discover_svc_id(std::optional< peer_id_t > const& found) const = 0;
 };
 
 struct HomeBlocksStats {

src/lib/homeblks_impl.cpp

@@ -14,7 +14,8 @@
  *
  *********************************************************************************/
 #include <algorithm>
-
+#include <boost/uuid/uuid.hpp>
+#include <boost/uuid/nil_generator.hpp>
 #include <iomgr/io_environment.hpp>
 #include <homestore/homestore.hpp>
 #include <homestore/replication_service.hpp>
@@ -119,8 +120,8 @@ class HBReplApp : public homestore::ReplApplication {
 
     homestore::replica_id_t get_my_repl_id() const override { return hb_->our_uuid(); }
 
-    void destroy_repl_dev_listener(homestore::group_id_t) override {
-        LOGERROR("destroy_repl_dev_listener Unimplimented");
+    void destroy_repl_dev_listener(homestore::group_id_t gid) override {
+        LOGI("Destroying repl dev listener for group_id {}", boost::uuids::to_string(gid));
     }
 
 private:
@@ -182,7 +183,11 @@ void HomeBlocksImpl::init_homestore() {
                            .start(hs_input_params{.devices = device_info, .app_mem_size = app_mem_size},
                                   [this]() { register_metablk_cb(); });
     if (need_format) {
-        LOGI("We are starting for the first time. Formatting HomeStore. ");
+        auto ret = app->discover_svc_id(std::nullopt);
+        DEBUG_ASSERT(ret.has_value(), "UUID should be generated by application.");
+        our_uuid_ = ret.value();
+        LOGINFO("We are starting for the first time on svc_id: [{}]. Formatting HomeStore. ",
+                boost::uuids::to_string(our_uuid()));
         if (has_data_dev && has_fast_dev) {
             // NOTE: chunk_size, num_chunks only has to specify one, can be deduced from each other.
             homestore::hs()->format_and_start({
@@ -216,6 +221,12 @@ void HomeBlocksImpl::init_homestore() {
         }
         // repl_app->on_repl_devs_init_completed();
         superblk_init();
+    } else {
+        // we are starting on an existing system;
+        DEBUG_ASSERT(our_uuid() != boost::uuids::nil_uuid(), "UUID should be recovered from HB superblock!");
+        // now callback to application to nofity the uuid so that we are treated as an existing system;
+        app->discover_svc_id(our_uuid());
+        LOGINFO("We are starting on [{}].", boost::uuids::to_string(our_uuid_));
     }
 
     recovery_done_ = true;
@@ -228,6 +239,7 @@ void HomeBlocksImpl::superblk_init() {
     sb_->version = HB_SB_VER;
     sb_->boot_cnt = 0;
     sb_->init_flag(0);
+    sb_->svc_id = our_uuid_;
     sb_.write();
 }
 
@@ -247,6 +259,10 @@ void HomeBlocksImpl::on_hb_meta_blk_found(sisl::byte_view const& buf, void* cook
 
     ++sb_->boot_cnt;
 
+    our_uuid_ = sb_->svc_id;
+
+    LOGI("HomeBlks superblock loaded, boot_cnt: {}, svc_id: {}", sb_->boot_cnt, boost::uuids::to_string(our_uuid_));
+
     // avoid doing sb meta blk write in callback which will cause deadlock;
     // the 1st CP should flush all dirty SB before taking traffic;
 }

src/lib/homeblks_impl.hpp

@@ -36,6 +36,7 @@ class HomeBlocksImpl : public HomeBlocks, public VolumeManager, public std::enab
         uint32_t version;
         uint32_t flag;
         uint64_t boot_cnt;
+        peer_id_t svc_id;
 
         void init_flag(uint32_t f) { flag = f; }
         void set_flag(uint32_t bit) { flag |= bit; }
@@ -67,6 +68,7 @@ class HomeBlocksImpl : public HomeBlocks, public VolumeManager, public std::enab
 
     bool recovery_done_{false};
     superblk< homeblks_sb_t > sb_;
+    peer_id_t our_uuid_;
 
 public:
     explicit HomeBlocksImpl(std::weak_ptr< HomeBlocksApplication >&& application);
@@ -84,10 +86,7 @@ class HomeBlocksImpl : public HomeBlocks, public VolumeManager, public std::enab
     HomeBlocksStats get_stats() const final;
     iomgr::drive_type data_drive_type() const final;
 
-    peer_id_t our_uuid() const final {
-        // not expected to be called;
-        return peer_id_t{};
-    }
+    peer_id_t our_uuid() const final { return our_uuid_; }
 
     /// VolumeManager
     NullAsyncResult create_volume(VolumeInfo&& vol_info) final;

src/lib/volume/tests/test_common.hpp

@@ -25,6 +25,7 @@
 #include <sisl/settings/settings.hpp>
 #include <boost/uuid/string_generator.hpp>
 #include <boost/uuid/nil_generator.hpp>
+#include <boost/uuid/random_generator.hpp>
 #include <chrono>
 #include <iostream>
 #include <thread>
@@ -82,7 +83,9 @@ class HBTestHelper {
             return devs;
         }
 
-        peer_id_t discover_svcid(std::optional< peer_id_t > const&) const override { return helper_.svc_id(); }
+        std::optional< peer_id_t > discover_svc_id(std::optional< peer_id_t > const&) const override {
+            return helper_.svc_id();
+        }
 
         uint64_t app_mem_size() const override {
             // return SISL_OPTIONS["app_mem_size"].as< uint64_t >();
@@ -99,7 +102,7 @@ class HBTestHelper {
         sisl::logging::SetLogPattern("[%D %T%z] [%^%L%$] [%n] [%t] %v");
 
         // init svc_id_
-        svc_id_ = boost::uuids::nil_uuid();
+        svc_id_ = boost::uuids::random_generator()();
 
         // init device list
         init_dev_list(true /*init_device*/);