#Lsm imagezilla code#

Some saw duty in the Korea War and three LSMRs were on duty in the Viet Nam War.

Most saw enemy action in the Pacific theatre of the war. There were 554 of this unique class of ship commissioned during the war, 60 of which were converted to LSMRs (Rocket Ships). When the ship was ready to withdraw, the stern anchor was pulled in, retracting the ship from the beach. When an LSM approached a beach, the stern anchor, a design adapted from the LCI, was dropped and a chain played out, helping her go straight to the beach. The nickname “Sandscrapers” stuck, as the ships drew only six feet of water at the bow when loaded. The LSM was highly maneuverable, with a flat bottom that slipped across sand bars and beaches. The high bow featured doors like those on the LST (landing ship, tank), opening with a loading ramp for jeeps, trucks, and tanks to drive directly from the ship’s well deck onto the beach. The LSM was in charge of delivering tanks, various other equipment and Marines to shore.

#Lsm imagezilla code#

It didn't have to be hauled to its destination like a DUKW, manufacturer's code for a type of military wheeled amphibious landing-craft, or a Higgins boat.

An LSM was the smallest of the ocean-going ships. The LSM held a crew of 54 enlisted men and four officers, and were used in the Pacific to transport equipment, supplies and troops during the final campaigns of World War II. In our demo, users can better understand how each compaction happens through the compaction animation, and they can also examine the internal trade-off across different metrics (e.g., ingest, point lookup and range lookup).Needing a landing ship somewhere between the size and displacement of an LCI (Landing Craft, Infantry) and an LST (Landing Ship, Tank), the Navy turned the problem over to its architects and designers who came up with the compact and maneuverable LSM (Landing Ship, Medium). To demonstrate the operational flow of a family of state-of-the-art LSM compaction strategies, we introduce Compactionary. RocksDB supports various data movement policy including Least Overlapping, Coldest, Oldest and Tombstone Density. Granularity of one or more files (granularity) according to the level saturation, file staleness and spalce amplification (trigger). This design does not implement partial compactions, and thus it does not need a data movement policy.Ī more complex example is RocksDB which applies 1-leveling (tiering for level 1 and leveling for others) (data layout) and compactions are performed at the This allows us to create the taxonomy of the universe of LSM compaction strategies, including all the classical as well as new ones.įor example, AsterixDB has a leveled-based LSM-tree (data layout) that compacts whole levels at a time (granularity) once a level reaches a nominal size (trigger). The above four design primitives provide a structured decomposition of arbitrary compaction strategies. This process is known as partial compaction. If Level i grows beyond a threshold, a compaction is triggered and one file (or a subset of files) from Level i is chosen to be compacted with files from Level i + 1 that have an overlapping key-range. To amortize data movement, and thus, avoid latency spikes, state-of-the-art LSM-engines organize data into smaller files, and perform compactions at the granularity of files instead of levels. Recently hybrid compaction policies (e.g., the hybrid compaction as follows) fuse leveling and tiering in a single tree to strike a balance between the read and write throughput based on workload specifications. With tiering, every level must accumulate T runs before they are sort-merged. In leveling, each level may have at most one run, and every time a run in Level i − 1 (i ≥ 1) is moved to Level i, it is greedily sort-merged with the run from Level i, if it exists. Classically, LSM-trees support two merging policies: leveling and tiering.