two unrelated changes: release rb_mut before getting header_mut on read path (breaks delta tuples), and implement first-cut support for pulling in statistics when reopening logstores (required for correct recovery)

git-svn-id: svn+ssh://svn.corp.yahoo.com/yahoo/yrl/labs/pnuts/code/logstore@868 8dad8b1f-cf64-0410-95b6-bcf113ffbcfe

logstore.cpp

@@ -50,10 +50,6 @@ logtable<TUPLE>::logtable(pageid_t internal_region_size, pageid_t datapage_regio
     this->internal_region_size = internal_region_size;
     this->datapage_region_size = datapage_region_size;
     this->datapage_size = datapage_size;
-
-    c0_stats = merge_mgr->get_merge_stats(0);
-    merge_mgr->new_merge(0);
-    c0_stats->starting_merge();
 }
 
 template<class TUPLE>
@@ -104,7 +100,13 @@ recordid logtable<TUPLE>::allocTable(int xid)
     //create the small tree
     tree_c1 = new diskTreeComponent(xid, internal_region_size, datapage_region_size, datapage_size, stats);
 
-    update_persistent_header(xid);
+    c0_stats = merge_mgr->get_merge_stats(0);
+    merge_mgr->new_merge(0);
+    c0_stats->starting_merge();
+
+    update_persistent_header(xid, 1);
+    update_persistent_header(xid, 2);
+
 
     return table_rec;
 }
@@ -114,9 +116,20 @@ void logtable<TUPLE>::openTable(int xid, recordid rid) {
   Tread(xid, table_rec, &tbl_header);
   tree_c2 = new diskTreeComponent(xid, tbl_header.c2_root, tbl_header.c2_state, tbl_header.c2_dp_state, 0);
   tree_c1 = new diskTreeComponent(xid, tbl_header.c1_root, tbl_header.c1_state, tbl_header.c1_dp_state, 0);
+
+  merge_mgr->get_merge_stats(1)->bytes_out = tbl_header.c1_base_size;
+  merge_mgr->get_merge_stats(1)->base_size = tbl_header.c1_base_size;
+  merge_mgr->get_merge_stats(1)->mergeable_size = tbl_header.c1_mergeable_size;
+  merge_mgr->get_merge_stats(2)->base_size = tbl_header.c2_base_size;
+  merge_mgr->get_merge_stats(2)->bytes_out = tbl_header.c2_base_size;
+
+  c0_stats = merge_mgr->get_merge_stats(0);
+  merge_mgr->new_merge(0);
+  c0_stats->starting_merge();
+
 }
 template<class TUPLE>
-void logtable<TUPLE>::update_persistent_header(int xid) {
+void logtable<TUPLE>::update_persistent_header(int xid, int merge_level) {
 
     tbl_header.c2_root = tree_c2->get_root_rid();
     tbl_header.c2_dp_state = tree_c2->get_datapage_allocator_rid();
@@ -125,6 +138,17 @@ void logtable<TUPLE>::update_persistent_header(int xid) {
     tbl_header.c1_dp_state = tree_c1->get_datapage_allocator_rid();
     tbl_header.c1_state = tree_c1->get_internal_node_allocator_rid();
     
+    if(merge_level == 1) {
+      tbl_header.c1_base_size = merge_mgr->get_merge_stats(1)->bytes_out;
+      tbl_header.c1_mergeable_size = merge_mgr->get_merge_stats(1)->mergeable_size;
+    } else if(merge_level == 2) {
+      tbl_header.c1_mergeable_size = 0;
+      tbl_header.c2_base_size = merge_mgr->get_merge_stats(2)->bytes_out;
+    } else {
+      assert(merge_level == 1 || merge_level == 2);
+      abort();
+    }
+
     Tset(xid, table_rec, &tbl_header);    
 }
 
@@ -218,8 +242,8 @@ datatuple * logtable<TUPLE>::findTuple(int xid, const datatuple::key_t key, size
         ret_tuple = (*rbitr)->create_copy();
     }
 
-    rwlc_readlock(header_mut);  // has to be before rb_mut, or we could merge the tuple with itself due to an intervening merge
     pthread_mutex_unlock(&rb_mut);
+    rwlc_readlock(header_mut);  // XXX: FIXME with optimisitic concurrency control.  Has to be before rb_mut, or we could merge the tuple with itself due to an intervening merge
 
     bool done = false;
     //step: 2 look into first in tree if exists (a first level merge going on)
@@ -371,8 +395,8 @@ datatuple * logtable<TUPLE>::findTuple_first(int xid, datatuple::key_t key, size
     {
         DEBUG("Not in mem tree %d\n", tree_c0->size());
 
-        rwlc_readlock(header_mut);
         pthread_mutex_unlock(&rb_mut);
+        rwlc_readlock(header_mut); // XXX FIXME WITH OCC!!
 
         //step: 2 look into first in tree if exists (a first level merge going on)
         if(get_tree_c0_mergeable() != NULL)

logstore.h

@@ -81,7 +81,7 @@ public:
       merge_mgr->get_merge_stats(1);
     }
     void set_tree_c0_mergeable(memTreeComponent<datatuple>::rbtree_ptr_t newtree){tree_c0_mergeable = newtree; bump_epoch(); }
-    void update_persistent_header(int xid);
+    void update_persistent_header(int xid, int merge_level);
 
     void setMergeData(logtable_mergedata * mdata);
     logtable_mergedata* getMergeData(){return mergedata;}
@@ -97,6 +97,9 @@ public:
         recordid c1_root;
         recordid c1_state;
         recordid c1_dp_state;
+        pageid_t c2_base_size;
+        pageid_t c1_mergeable_size;
+        pageid_t c1_base_size;
     };
 
     logtable_mergedata * mergedata;

mergeStats.h

@@ -25,9 +25,9 @@ class mergeStats {
       merge_level(merge_level),
       merge_count(0),
       base_size(0),
+      mergeable_size(0),
       target_size(target_size),
       current_size(0),
-      mergeable_size(0),
       bytes_out_with_overhead(0),
       bytes_out(0),
       num_tuples_out(0),
@@ -114,14 +114,17 @@ class mergeStats {
     friend class mergeManager;
 
     struct timespec last_tick;
-
+  public: // XXX only accessed during initialization.
     pageid_t base_size;
+    pageid_t mergeable_size;  // protected by mutex.
+  protected:
     pageid_t target_size;
     pageid_t current_size;
-    pageid_t mergeable_size;  // protected by mutex.
 
     pageid_t bytes_out_with_overhead;// How many bytes did we write (including internal tree nodes)?
+  public:
     pageid_t bytes_out;            // How many bytes worth of tuples did we write?
+  protected:
     pageid_t num_tuples_out;       // How many tuples did we write?
     pageid_t num_datapages_out;    // How many datapages?
     pageid_t bytes_in_small;       // How many bytes from the small input tree (for C0, we ignore tree overheads)?

merger.cpp

@@ -15,9 +15,6 @@ int merge_scheduler::addlogtable(logtable<datatuple> *ltable)
     // initialize merge data
     ltable->set_tree_c0_mergeable(NULL);
     
-    mdata->diskmerge_args = new merger_args;
-    mdata->memmerge_args = new merger_args;
-    
     mergedata.push_back(std::make_pair(ltable, mdata));
     return mergedata.size()-1;
     
@@ -25,14 +22,6 @@ int merge_scheduler::addlogtable(logtable<datatuple> *ltable)
 
 merge_scheduler::~merge_scheduler()
 {
-    for(size_t i=0; i<mergedata.size(); i++)
-    {
-        logtable<datatuple> *ltable = mergedata[i].first;
-        logtable_mergedata *mdata = mergedata[i].second;
-
-        delete mdata->diskmerge_args;
-        delete mdata->memmerge_args;
-    }
     mergedata.clear();
 
 }
@@ -76,26 +65,11 @@ void merge_scheduler::startlogtable(int index, int64_t MAX_C0_SIZE)
     DEBUG("Tree C1 is %lld\n", (long long)ltable->get_tree_c1()->get_root_rec().page);
     DEBUG("Tree C2 is %lld\n", (long long)ltable->get_tree_c2()->get_root_rec().page);
 
-    struct merger_args diskmerge_args= {
-        ltable, 
-        0, //max_tree_size No max size for biggest component
-                };
-
-    *mdata->diskmerge_args = diskmerge_args;
-
-    struct merger_args memmerge_args =
-        {
-            ltable,
-            (int64_t)(MAX_C0_SIZE), // XXX why did this multiply by R^2 before??
-        };
-    
-    *mdata->memmerge_args = memmerge_args;
-
     void * (*diskmerger)(void*) = diskMergeThread;
     void * (*memmerger)(void*) = memMergeThread;
 
-    pthread_create(&mdata->diskmerge_thread, 0, diskmerger, mdata->diskmerge_args);
+    pthread_create(&mdata->diskmerge_thread, 0, diskmerger, ltable);
-    pthread_create(&mdata->memmerge_thread, 0, memmerger, mdata->memmerge_args);
+    pthread_create(&mdata->memmerge_thread, 0, memmerger, ltable);
     
 }
 
@@ -135,13 +109,11 @@ void* memMergeThread(void*arg)
 
     int xid;
 
-    merger_args * a = (merger_args*)(arg);
+    logtable<datatuple> * ltable = (logtable<datatuple>*)arg;
-
-    logtable<datatuple> * ltable = a->ltable;
     assert(ltable->get_tree_c1());
     
     int merge_count =0;
-    mergeStats * stats = a->ltable->merge_mgr->get_merge_stats(1);
+    mergeStats * stats = ltable->merge_mgr->get_merge_stats(1);
     
     while(true) // 1
     {
@@ -227,7 +199,7 @@ void* memMergeThread(void*arg)
         double new_c1_size = stats->output_size();
         pthread_cond_signal(&ltable->c0_needed);
 
-        ltable->update_persistent_header(xid);
+        ltable->update_persistent_header(xid, 1);
         Tcommit(xid);
 
         ltable->merge_mgr->finished_merge(1);
@@ -261,8 +233,10 @@ void* memMergeThread(void*arg)
           ltable->set_tree_c1(new diskTreeComponent(xid, ltable->internal_region_size, ltable->datapage_region_size, ltable->datapage_size, stats));
 
           pthread_cond_signal(&ltable->c1_ready);
-
+          pageid_t old_bytes_out = stats->bytes_out;
-          ltable->update_persistent_header(xid);
+          stats->bytes_out = 0; // XXX HACK
+          ltable->update_persistent_header(xid, 1);
+          stats->bytes_out = old_bytes_out;
           Tcommit(xid);
 
         }
@@ -285,14 +259,12 @@ void *diskMergeThread(void*arg)
 {
     int xid;
 
-    merger_args * a = (merger_args*)(arg);
+    logtable<datatuple> * ltable = (logtable<datatuple>*)arg;
-
-    logtable<datatuple> * ltable = a->ltable;
     assert(ltable->get_tree_c2());
 
 
     int merge_count =0;
-    mergeStats * stats = a->ltable->merge_mgr->get_merge_stats(2);
+    mergeStats * stats = ltable->merge_mgr->get_merge_stats(2);
     
     while(true)
     {
@@ -378,7 +350,7 @@ void *diskMergeThread(void*arg)
 
         DEBUG("dmt:\tUpdated C2's position on disk to %lld\n",(long long)-1);
         // 13
-        ltable->update_persistent_header(xid);
+        ltable->update_persistent_header(xid, 2);
         Tcommit(xid);
 
         ltable->merge_mgr->finished_merge(2);

merger.h

@@ -12,23 +12,11 @@
 static const int RB_TREE_OVERHEAD = 400;
 static const double MIN_R = 3.0;
 
-struct merger_args
-{
-    logtable<datatuple> * ltable;
-    int64_t max_size;
-};
-
 struct logtable_mergedata
 {
     //merge threads
     pthread_t diskmerge_thread;
     pthread_t memmerge_thread;
-
-    //merge args 1
-    struct merger_args *diskmerge_args;
-    //merge args 2
-    struct merger_args *memmerge_args;
-    
 };
 
 class merge_scheduler