{"id":13702690,"url":"https://github.com/basho/leveldb","last_synced_at":"2025-04-04T20:12:54.382Z","repository":{"id":2319823,"uuid":"3280270","full_name":"basho/leveldb","owner":"basho","description":"Clone of http://code.google.com/p/leveldb/","archived":false,"fork":false,"pushed_at":"2022-06-21T09:58:44.000Z","size":5356,"stargazers_count":408,"open_issues_count":36,"forks_count":177,"subscribers_count":117,"default_branch":"develop","last_synced_at":"2025-03-28T19:08:39.237Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":"","language":"C++","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"bsd-3-clause","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/basho.png","metadata":{"files":{"readme":"README","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null}},"created_at":"2012-01-27T04:49:26.000Z","updated_at":"2024-02-09T02:52:37.000Z","dependencies_parsed_at":"2022-09-05T14:50:37.814Z","dependency_job_id":null,"html_url":"https://github.com/basho/leveldb","commit_stats":null,"previous_names":[],"tags_count":56,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/basho%2Fleveldb","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/basho%2Fleveldb/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/basho%2Fleveldb/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/basho%2Fleveldb/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/basho","download_url":"https://codeload.github.com/basho/leveldb/tar.gz/refs/heads/develop","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":247242681,"owners_count":20907134,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2024-08-02T21:00:40.884Z","updated_at":"2025-04-04T20:12:54.363Z","avatar_url":"https://github.com/basho.png","language":"C++","readme":"leveldb: A key-value store\nAuthors: Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)\n\nThe original Google README is now README.GOOGLE.\n\n** Introduction\n\nThis repository contains the Google source code as modified to benefit\nthe Riak environment.  The typical Riak environment has two attributes\nthat necessitate leveldb adjustments, both in options and code:\n\n- production servers: Riak often runs in heavy Internet environments:\n  servers with many CPU cores, lots of memory, and 24x7 disk activity.\n  Basho's leveldb takes advantage of the environment by adding\n  hardware CRC calculation, increasing Bloom filter accuracy, and\n  defaulting to integrity checking enabled.\n\n- multiple databases open: Riak opens 8 to 128 databases\n  simultaneously.  Google's leveldb supports this, but its background\n  compaction thread can fall behind.  leveldb will \"stall\" new user\n  writes whenever the compaction thread gets too far behind.  Basho's\n  leveldb modification include multiple thread blocks that each\n  contain prioritized threads for specific compaction activities.\n\nDetails for Basho's customizations exist in the leveldb wiki:\n\n  http://github.com/basho/leveldb/wiki\n\n\n** Branch pattern\n\nThis repository follows the Basho standard for branch management \nas of November 28, 2013.  The standard is found here:\n\nhttps://github.com/basho/riak/wiki/Basho-repository-management\n\nIn summary, the \"develop\" branch contains the most recently reviewed\nengineering work.  The \"master\" branch contains the most recently\nreleased work, i.e. distributed as part of a Riak release.\n\n\n** Basic options needed\n\nThose wishing to truly savor the benefits of Basho's modifications\nneed to initialize a new leveldb::Options structure similar to the\nfollowing before each call to leveldb::DB::Open:\n\n    leveldb::Options * options;\n\n    options=new Leveldb::Options;\n\n    options.filter_policy=leveldb::NewBloomFilterPolicy2(16);\n    options.write_buffer_size=62914560;  // 60Mbytes\n    options.total_leveldb_mem=2684354560; // 2.5Gbytes (details below)\n    options.env=leveldb::Env::Default();\n\n\n** Memory plan\n\nBasho's leveldb dramatically departed from Google's original internal\nmemory allotment plan with Riak 2.0.  Basho's leveldb uses a methodology\ncalled flexcache.  The technical details are here:\n\n   https://github.com/basho/leveldb/wiki/mv-flexcache\n\nThe key points are:\n\n- options.total_leveldb_mem is an allocation for the entire process,\n  not a single database\n\n- giving different values to options.total_leveldb_mem on subsequent Open\n  calls causes memory to rearrange to current value across all databases\n\n- recommended minimum for Basho's leveldb is 340Mbytes per database.  \n\n- performance improves rapidly from 340Mbytes to 2.5Gbytes per database (3.0Gbytes\n  if using Riak's active anti-entropy).  Even more is nice, but not as helpful.\n\n- never assign more than 75% of available RAM to total_leveldb_mem.  There is\n  too much unaccounted memory overhead (worse if you use tcmalloc library).\n\n- options.max_open_files and options.block_cache should not be used.\n  \n","funding_links":[],"categories":["Stores"],"sub_categories":["[`leveldown-basho`][leveldown-basho]"],"project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fbasho%2Fleveldb","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fbasho%2Fleveldb","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fbasho%2Fleveldb/lists"}