Welcome to the documentations of SWC-DB© !

SWC-DB© (Super Wide Column Database) - a High Performance Scalable Database


Introduction to the SWC-DB

The SWC-DB (Super Wide Column Database) a Super Fast database management system designed to handle Yottabytes+ on a quadrillion base of entries. SWC-DB latest-release is version 0.5.0 available at github.com/kashirin-alex/swc-db more details at Getting SWC-DB .

The proven test with SWC-DB v0.4.9, on one machine(CPU Intel E3-1246V3 RAM 32GB SW-RAID 2x 2TB-7200rpm) run the DB and the Client, capabilities standing is a dozen terabytes of raw-data with 100+billion of record entries with performace input of ~250,000+ cells a second and random scan/select of one entry surrounds the microseconds to milliseconds, whereas performance varies on applied configurations and hardware. Testing facillity is required for in deep and further testing.

The What is SWC-DB? checklist

Is it? ? Comments
    Legend:
- Yes
–✔ - Require Enabling Feature
- No
a Key Value DB  
a Wide Column Database DB  
a NOSQL (Not Only Structual Query Language) DB  
a SQL (Structual Query Language) DB no joins
a DB with ACID(concept) for a single data-entry write with acknowledgment on base of one data-entry(cell)
a DB with ACID(concept) for a many data-entries write with acknowledgment many data-entries(cells) with one request, problem - one entry can exist while other yet to exist
a Relational DB achievable by the client-side
a Time Series DB without relational propotions
an Object Oriented DB –✔ binary key(Fractions) and value allowed, user defined Serialization IO or/and Serializations available with the SERIAL column-type
a XML DB / Tripel Stores –✔ require Native XML Client process XML-schema to Database structure
a Schema Free DB except to data/column type, schema/column-definition is without inner data schematics
a DB with User Concepts (Access Controls)  
a Shard Partitioning DB  
a Spatial DB user defined Fractions order and sequence in a Cell Key
a Variable Key Sequences DB infinite size (indefinite other limitation apply )
a Distributed + Scalable DB O(1) performance
a DB with Multihoming Capabilities  
a DB with Nanosecond Precision  
a DB supporting variety of File-Systems any File System which can implement the Base class SWC::FS::FileSystem
a DB with Data Replication Support –✔ File System dependant
a Versioned Data DB automatic or user defined versions by Desc/Asc with Max Versions to Keep
a DB supporting an “Atomic“ Counter Value  
a DB supporting Query of Multiple Sequences multiple Columns with multiple Intervals in a Column
a Document/Files stores DB user defined Meta/Header & Key-Fractions(file-path) structure whereas anomaly of use is at file-size above Range-Block-size cfg
a Super Wide Column DB supporting 16777216(2^24,uint24) number of Fractions, max 2^24 bytes a Fraction and total size of a key upto 2^32 bytes
a DB with Communications over Secure Layer(SSL) The total security of transactions require the underlying configured FileSystem and Clients to have & support a Secure Layer

The Differences of SWC-DB with Wide Column Databases

The major differences “Super Wide Column Database” has to commonly known Wide Column Databases are SWC-DB does not have Tables nor Namespaces and while cell key as known to be in Wide Column Database structured in timestamp, row, column-family and column-family-qualifier in SWC-DB a cell key is a list of Fractions with timestamp. The differences in SQL syntax, it is in-place of select columns from “table_name” with SWC-DB It is select [ where_clause [Columns-Intervals] ].
Considering to structure a Wide-Column-DB in SWC-DB it can be in these forms key=[F(row), F(column-family), F(column-family-qualifier)] or the actual column is named after Namespace, Table and Column Family with key=[F(row), F(column-family-qualifier)].

The Cell Key and Fractions in SWC-DB

The Fractions in SWC-DB cell-key let numerous “qualifiers”, as known to be, with a range-locator able to respond with the ranges applicable to the fractions of a scan specs. As a result a scan-spec of key=[>“”, >=”THIS”] will scan ranges that consist the “THIS” on comparator with a help of metacolumn that include, additionally to the key-begin and key-end of a range, the minimal and maximum values of the fractions in an aligned manner. Hence the name “Super Wide Column“ a column can have cells with one key [F(1st)] second key [F(1st), F(2nd)] third key [F(1st), F(2nd), F(3rd), .. ] and the scan/select is possible on [F(1st)] and above that will return all the cells having fraction one equal “1st ” and so as without further indexations to select cells with key [>F(), F(2nd)] returning the cells with second fraction equal “2nd”.

The Comparators in SWC-DB

The Comparators available in SWC-DB are NONE, PF ,GT, GE, EQ, LE, LT, NE, RE and domain-object(Fully/Partially sub/sup set) SBS, SPS, POSBS, POSPS, FOSBS and FOSPS, while some Comparators have limitations for range-locator as regexp is evaluated as NONE being anything-match. Additionally the conditions of comparators applied on the corresponding “ key-sequence ” by column's schema that include LEXIC, VOLUME, FC_LEXIC, FC_VOLUME that define the sequence of cells in a range. If a prefix (PF) is desired than the choice will be the LEXIC or with FC_LEXIC as VOLUME (volumetric) will not correspond to the char-byte sequence while if desired to have for example a decimal sequence of 0, 1, 2 .. 11 the VOLUME is the right choice whereas the FC_VOLUME unlike tree-wise on fraction keeps the sequence of smaller key fractions-count at the beginning in the range.

The Master Ranges and Meta Ranges in SWC-DB

SWC-DB use a self-explanatory master-ranges that define ranges to meta-ranges of data-ranges(cells-range) whereas on range-locator scan includes the Key comparison on the comparators of request, resulting in most narrowed ranges for the scan of cells. For the purpose SWC-DB have reserved columns
1: Ranges(“SYS_MASTER_LEXIC”)
2: Ranges(“SYS_MASTER_VOLUME”)
3: Ranges(“SYS_MASTER_FC_LEXIC”)
4: Ranges(“SYS_MASTER_FC_VOLUME”)
5: Ranges(“SYS_META_LEXIC”)
6: Ranges(“SYS_META_VOLUME”)
7: Ranges(“SYS_META_FC_LEXIC”)
8: Ranges(“SYS_META_FC_VOLUME”)
9: Statistics(“SYS_STATS”)
The Statistics column used for internal systems monitoring and it can be used like any other counter column (keeping for the purpose) with fraction of [period, role, instance, metric] with a counter value.

The Persistent Storage in SWC-DB

The storage-form in the SWC-DB on FS is based by column-id and range-id, that on path consist CellStores and CommitLog files while at any point one server is responsible for a range-id on column-id and of a path root. The CellStores are files storing Cells in serialized form that are after latest compaction whereas Commit-Log is Fragments of current added data, one fragment is written at a time on a threshold reach or on shutdown.

The limitations that can be overseen with SWC-DB

✗ Maximum number of columns, it is store-size of uint64(2^64) – 10(reserved cols) which can be improved by CID to be a string-type.
✗ Maximum size of Value or Key-Fraction(after serialization), it is 4GB, while for such data size other limitations apply.

The capabilities to expect from SWC-DB

✔ A Manager-Root with definitions of 1K^2 ranges (a use of 1 GB RAM) is a definition of 1K^4 Meta-Ranges that sums-down to 1K^8 Data-Ranges, with range-size configuration to 10GB that makes a total storage volume for a cell size average of 256KB to be a quarter of Yotta Byte.
✔ A client can read at 100%(while Client's and Ranger's are equivalent) bandwidth, considering a perfect scan case of each client is requesting on different ranges, number of clients at a given time can be by the number of data Rangers using 100% bandwidth each.
✔ Maximum number of concurrent connections to a given server instance, it is the total available ports on the server by the number of configured IPv4 and IPv6 with support of multi-homed / multiple interfaces.

The Failure Tolerance of SWC-DB

✔ A failed request to a Manager is a connection fail-over to next in list from ‘swc.mngr.host' configuration.
✔ A failed request to a Ranger(Master, Meta, Data)-N is a fail-over to the new newly assigned Ranger(addr) by Manager.
✔ Manager, on interval or shut-down state of a managed Ranger(either role), request to load ranges to another Ranger.
✔ Distribute File System, depends on the system and it's feature of routing to a datanode.
✔ Managers or Rangers in case of a connection or file-descriptor failure try to reconnect to the DFS.
✔ Communications security, SSL applicable between servers for non-secure networks.
✔ Communication over-heads of resolved-data of column-name, RID-location and Ranger-address are kept on TTL/KA. In worst case of outdated data being used with a request the Ranger return an error of a NOT_LOADED_RANGE.


The Documentations Table of Contents


DEVELOPMENT ABSTRACT

https://alex.kashirin.family/swc-DB.pdf


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