Took out the cache repopulate idea. Now we will only have warnings

of problems.

I realized we can't reliably tell how big the cache is while the system
is running.  There's a window where write/append has added / is adding
a journal file but hasn't told Cache about it yet.  This capability will
have to wait for now.

This shouldn't be a problem because in theory, we will no longer have
data whose size is not consistent with metadata stored outside of the file.
If we do, it means there was either a hard failure, or SM was killed.
Either way, SM will be restarted and the cache will populate its meta
fresh then.

storage-manager/src/Cache.cpp

@@ -356,19 +356,6 @@ void Cache::configListener()
     }
 }
 
-void Cache::repopulate()
-{
-    boost::unique_lock<boost::mutex> sl(lru_mutex);
-    
-    for (auto &pcache : prefixCaches)
-        pcache.second->repopulate();
-}
-
-void Cache::repopulate(const boost::filesystem::path &p)
-{
-    getPCache(p).repopulate();
-}
-
 }
 
 

storage-manager/src/Cache.h

@@ -92,11 +92,6 @@ class Cache : public boost::noncopyable , public ConfigListener
         void shutdown();
         void printKPIs() const;
         
-        // Used to update accounting variables in the PrefixCaches when a potential error
-        // is detected.
-        void repopulate();
-        void repopulate(const boost::filesystem::path &prefix);
-        
         // test helpers
         const boost::filesystem::path &getCachePath() const;
         const boost::filesystem::path &getJournalPath() const;

storage-manager/src/PrefixCache.cpp

@@ -127,13 +127,7 @@ PrefixCache::~PrefixCache()
     */
 }
 
-void PrefixCache::repopulate()
-{
-    lru_mutex.lock();
-    populate(false);
-}
-
-void PrefixCache::populate(bool useSync)
+void PrefixCache::populate()
 {
     Synchronizer *sync = Synchronizer::get();
     bf::directory_iterator dir(cachePrefix);
@@ -151,14 +145,12 @@ void PrefixCache::populate(bool useSync)
             auto last = lru.end();
             m_lru.insert(--last);
             currentCacheSize += bf::file_size(*dir);
-            if (useSync)
             newObjects.push_back(p.filename().string());
         }
         else if (p != cachePrefix/downloader->getTmpPath())
             logger->log(LOG_WARNING, "Cache: found something in the cache that does not belong '%s'", p.string().c_str());
         ++dir;
     }
-    if (useSync)
     sync->newObjects(firstDir, newObjects);
     newObjects.clear();
     
@@ -174,7 +166,6 @@ void PrefixCache::populate(bool useSync)
             {
                 size_t s = bf::file_size(*dir);
                 currentCacheSize += s;
-                if (useSync)
                 newJournals.push_back(pair<string, size_t>(p.stem().string(), s));
             }
             else
@@ -185,7 +176,6 @@ void PrefixCache::populate(bool useSync)
         ++dir;
     }
     lru_mutex.unlock();
-    if (useSync)
     sync->newJournalEntries(firstDir, newJournals);
 }
 
@@ -399,10 +389,9 @@ void PrefixCache::deletedJournal(size_t size)
     else
     {
         ostringstream oss;
-        oss << "PrefixCache::deletedJournal(): Detected an accounting error." <<
-        "  Reloading cache metadata, this will pause IO activity briefly.";
+        oss << "PrefixCache::deletedJournal(): Detected an accounting error.";
         logger->log(LOG_WARNING, oss.str().c_str());
-        populate(false);
+        currentCacheSize = 0;
     }
 }
 
@@ -425,10 +414,9 @@ void PrefixCache::deletedObject(const string &key, size_t size)
         else
         {
             ostringstream oss;
-            oss << "PrefixCache::deletedObject(): Detected an accounting error." <<
-            "  Reloading cache metadata, this will pause IO activity briefly.";
+            oss << "PrefixCache::deletedObject(): Detected an accounting error.";
             logger->log(LOG_WARNING, oss.str().c_str());
-            populate(false);
+            currentCacheSize = 0;
         }
     }
 }

storage-manager/src/PrefixCache.h

@@ -77,11 +77,6 @@ class PrefixCache : public boost::noncopyable
         size_t getMaxCacheSize() const;
         void shutdown();
 
-        // clears out cache structures and reloads them from cache/journal dir contents
-        // needed to potentially repair the cache's accounting error after detecting
-        // an error.
-        void repopulate();
-
         // test helpers
         const boost::filesystem::path &getCachePath();
         const boost::filesystem::path &getJournalPath();
@@ -102,9 +97,7 @@ class PrefixCache : public boost::noncopyable
         SMLogging *logger;
         Downloader *downloader;
         
-        // useSync makes populate() tell Synchronizer about what it finds.
-        // set it to false when the system is already fully up.
-        void populate(bool useSync = true);
+        void populate();
         void _makeSpace(size_t size);
 
         /* The main PrefixCache structures */

storage-manager/src/Synchronizer.cpp

@@ -706,10 +706,8 @@ void Synchronizer::synchronizeWithJournal(const string &sourceFile, list<string>
             ostringstream oss;
             oss << "Synchronizer::synchronizeWithJournal(): detected a mismatch between file size and " <<
                 "length stored in the object name. object name = " << cloudKey << " length-in-name = " <<
-                MetadataFile::getLengthFromKey(cloudKey) << " real-length = " << bf::file_size(oldCachePath)
-                << ".  Reloading cache metadata, this will pause IO activity briefly.";
+                MetadataFile::getLengthFromKey(cloudKey) << " real-length = " << bf::file_size(oldCachePath);
             logger->log(LOG_WARNING, oss.str().c_str());
-            cache->repopulate(prefix);
         }
     }