WiredTiger release 1.2.1, 2012-06-15 ------------------------------------ This is a bugfix release. The changes are as follows: * Avoid a deadlock between eviction and checkpoint on the connection spinlock. * Allocate "desc" buffers in heap memory so that they are correctly aligned (fixes direct_io support on Linux). * Initialize the snapshot-avail list after cleaning it out, else we'll try and print a NULL pointer in VERBOSE mode. WiredTiger release 1.2.0, 2012-06-04 ------------------------------------ This release contains many bugfixes and improvements. The major changes are: [#138] Add support for transactions with coarse-grained durability. Transactions provide atomicity guarantees and rollback, and uncommitted changes are never written to disk. There is no on-disk log, so committed changes only become durable when the next checkpoint completes. Checkpoints are implemented by creating transactionally-consistent snapshots within data files. [#156] Fully support operations that make schema changes with multiple sessions open concurrently. [#159] Disable internal page key suffix compression if a custom collator is configured. This avoids issues with collators that require complete keys. [#167] Add support for durable snapshots within files. While a snapshot is active, the pages used by the snapshot will not be overwritten. If a file is accessed after a crash or application exit without calling WT_CONNECTION::close, any changes made after the last snapshot will be silently ignored. [#214, #216] Fixes for forcing eviction with small caches. WiredTiger release 1.1.5, 2012-04-26 ------------------------------------ Don't update a WT_REF after it has been unlocked. Add an operation to set a flag atomically, use it to avoid racing on page flags. Fix a race between sync and reading that could cause a segfault. WiredTiger release 1.1.4, 2012-04-16 ------------------------------------ Check the versions of autoconf, automake and libtool to avoid failures when trying to build from the github tree with versions that are too old. [#191] Create the schema table as part of creating the environment so that application threads don't race trying to create it later. [#193] Split-merge pages have to be reconciled to mark their parents dirty [#194] The dump utility should only output configuration that can be passed to WT_SESSION::create. Eviction fixes for out-of-cache update workloads: * Fix an unlikely bug where the EVICT_LRU flag was cleared when a page in the LRU queue was overwritten with itself during a walk. This led to an assertion failure when the page was later evicted. * Clear all unused eviction queue entries while holding the lru_lock. * Split WT_PAGE->flags so that there is no possibility of racing: (1) Move WT_PAGE_REC_* flags into WT_PAGE_MODIFY; (2) Use atomic operations to set and clear the remaining (2) page flags. Move the test/format threads setting into the CONFIG file. WiredTiger release 1.1.3, 2012-04-04 ------------------------------------ Fix the "exclusive" config for WT_SESSION::create. [#181] 1. Make it work for files within a single session. 2. Make it work for files across sessions. 3. Make other data sources consistent with files. Fix an eviction bug introduced into 1.1.2: when evicting a page with children, remove the children from the LRU eviction queue. Reduce the impact of clearing a page from the LRU queue by marking pages on the queue with a flag (WT_PAGE_EVICT_LRU). During an eviction walk, pin pages up to the root so there is no need to spin when attempting to lock a parent page. Use the EVICT_LRU page flag to avoid putting a page on the LRU queue multiple times. Layer dump cursors on top of any cursor type. Add a section on replacing the default system memory allocator to the tuning page. Typo in usage method for "wt write". Don't report range errors for config values that aren't well-formed integers. WiredTiger release 1.1.2, 2012-03-20 ------------------------------------ Add public-domain copyright notices to the extension code. test/format can now run multi-threaded, fixed two bugs it found: (1) When iterating backwards through a skiplist, we could race with an insert. (2) If eviction fails for a page, we have to assume that eviction has unlocked the reference. Scan row-store leaf pages twice when reading to reduce the overhead of the index array. Eviction race fixes: (1) Call __rec_review with WT_REFs: don't look at the page until we've checked the state. (2) Clear the eviction point if we hit it when discarding a child page, not just the parent. Eviction tuning changes, particularly for read-only, out-of-cache workloads. Only notify the eviction server if an application thread doesn't find any pages to evict, and then only once. Only spin on the LRU lock if there might be pages in the LRU queue to evict. Keep the current eviction point in memory and make the eviction walk run concurrent with LRU eviction. Every test now has err/out captured, and it is checked to assure it is empty at the end of every test. WiredTiger release 1.1.1, 2012-03-12 ------------------------------------ Default to a verbose build: that can be switched off by running "configure --enable-silent-rules"). Account for all memory allocated when reading a page into cache. Total memory usage is now much closer to the cache size when using many small keys and values. Have application threads trigger a retry forced page eviction rather than blocking eviction. This allows rec_evict.c to simply set the WT_REF state to WT_REF_MEM after all failures, and fixes a bug where pages on the forced eviction queue would end up with state WT_REF_MEM, meaning they could be chosen for eviction multiple times. Grow existing scratch buffers in preference to allocating new ones. Fix a race between threads reading in and then modifying a page. Get rid of the pinned flag: it is no longer used. Fix a race where btree files weren't completely closed before they could be re-opened. This behavior can be triggered by using a new session on every operation (see the new -S flag to the test/thread program). [#178] When connections are closed, create a session and discard the btree handles. This fixes a long-standing bug in closing a connection: if for any reason there are btree handles still open, we need a real session handle to close them. Really close btree handles: otherwise we can't safely remove or rename them. Fixes test failures in test_base02 (among others). Wait for application threads in LRU eviction to drain before walking a file. Fix a buffer size calculation when updating the root address of a file. Documentation fix: 10% of 1MB is 100KB. WiredTiger release 1.1.0, 2012-02-28 ------------------------------------ Add checks to the session.truncate method to ensure the start/stop cursors reference the same object and have been initialized. Implement cursor duplication via WT_SESSION::open_cursor. [#161] Switch to quiet builds by default. Fix with automake version < 1.11, use foreign mode so that fewer top-level files are required. If a session or connection method is about to return WT_NOTFOUND (some underlying object was not found), map it to ENOENT, only cursor methods return WT_NOTFOUND. [#163] Save and restore session->btree in schema ops to simplify calling code. [#164] Note the wiredtiger_open config string "multiprocess" is not yet supported. Move "root:F" and "version:F" entries for files into the value for "file:F", so there is only a single record per file. [NOTE: SCHEMA CHANGE] When parsing config strings, continue to the end of the string in case of repeated keys. [#124] Don't require shared libraries unless Python is configured. Add support for direct I/O, with the config "direct_io=(data,log)". Build with _GNU_SOURCE on Linux to enable O_DIRECT. Don't keep the last page of column stores pinned: it prevented eviction of large trees created from scratch. Allow application threads to evict pages from any tree: maintain a count of threads doing LRU in each tree and wait for activity to drain when closing.