mirror of https://github.com/schoebel/mars
187 lines
4.3 KiB
Plaintext
187 lines
4.3 KiB
Plaintext
#LyX 2.3 created this file. For more info see http://www.lyx.org/
|
|
\lyxformat 544
|
|
\begin_document
|
|
\begin_header
|
|
\save_transient_properties true
|
|
\origin unavailable
|
|
\textclass scrreprt
|
|
\begin_preamble
|
|
\usepackage{listings}
|
|
\end_preamble
|
|
\options abstracton,dvipsnames
|
|
\use_default_options true
|
|
\begin_modules
|
|
customHeadersFooters
|
|
enumitem
|
|
fixltx2e
|
|
\end_modules
|
|
\maintain_unincluded_children false
|
|
\language english
|
|
\language_package default
|
|
\inputencoding auto
|
|
\fontencoding global
|
|
\font_roman "default" "default"
|
|
\font_sans "default" "default"
|
|
\font_typewriter "default" "default"
|
|
\font_math "auto" "auto"
|
|
\font_default_family rmdefault
|
|
\use_non_tex_fonts false
|
|
\font_sc false
|
|
\font_osf false
|
|
\font_sf_scale 100 100
|
|
\font_tt_scale 100 100
|
|
\use_microtype false
|
|
\use_dash_ligatures false
|
|
\graphics default
|
|
\default_output_format default
|
|
\output_sync 0
|
|
\bibtex_command default
|
|
\index_command default
|
|
\paperfontsize 10
|
|
\spacing single
|
|
\use_hyperref true
|
|
\pdf_title "MARS Manual"
|
|
\pdf_author "Thomas Schöbel-Theuer"
|
|
\pdf_bookmarks true
|
|
\pdf_bookmarksnumbered false
|
|
\pdf_bookmarksopen false
|
|
\pdf_bookmarksopenlevel 1
|
|
\pdf_breaklinks true
|
|
\pdf_pdfborder true
|
|
\pdf_colorlinks true
|
|
\pdf_backref false
|
|
\pdf_pdfusetitle true
|
|
\papersize a4paper
|
|
\use_geometry true
|
|
\use_package amsmath 1
|
|
\use_package amssymb 1
|
|
\use_package cancel 1
|
|
\use_package esint 1
|
|
\use_package mathdots 1
|
|
\use_package mathtools 1
|
|
\use_package mhchem 1
|
|
\use_package stackrel 1
|
|
\use_package stmaryrd 1
|
|
\use_package undertilde 1
|
|
\cite_engine basic
|
|
\cite_engine_type default
|
|
\biblio_style plain
|
|
\use_bibtopic false
|
|
\use_indices false
|
|
\paperorientation portrait
|
|
\suppress_date false
|
|
\justification true
|
|
\use_refstyle 1
|
|
\use_minted 0
|
|
\index Index
|
|
\shortcut idx
|
|
\color #008000
|
|
\end_index
|
|
\leftmargin 3.7cm
|
|
\topmargin 2.7cm
|
|
\rightmargin 2.8cm
|
|
\bottommargin 2.3cm
|
|
\secnumdepth 3
|
|
\tocdepth 3
|
|
\paragraph_separation indent
|
|
\paragraph_indentation default
|
|
\is_math_indent 0
|
|
\math_numbering_side default
|
|
\quotes_style english
|
|
\dynamic_quotes 0
|
|
\papercolumns 1
|
|
\papersides 2
|
|
\paperpagestyle headings
|
|
\tracking_changes false
|
|
\output_changes false
|
|
\html_math_output 0
|
|
\html_css_as_file 0
|
|
\html_be_strict false
|
|
\end_header
|
|
|
|
\begin_body
|
|
|
|
\begin_layout Standard
|
|
MARS is a block-level storage replication system for long distances / flaky
|
|
networks under GPL.
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
It is a key component for achieving
|
|
\series bold
|
|
geo-redundancy
|
|
\series default
|
|
under Linux, for example Disaster Recovery (DR) at datacenter granularity,
|
|
and/or Location Transparency (LT) at VM / LV granularity.
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
It can help to increase
|
|
\series bold
|
|
reliability
|
|
\series default
|
|
via Sharding, and to
|
|
\series bold
|
|
save cost
|
|
\series default
|
|
by optional support for local storage in addition to network storage.
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
It eases
|
|
\series bold
|
|
load balancing
|
|
\series default
|
|
and
|
|
\series bold
|
|
background migration of data
|
|
\series default
|
|
, even over long distances.
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
MARS runs as a Linux kernel module.
|
|
The sysadmin interface is similar to DRBD, but its internal engine is completel
|
|
y different from DRBD: it works with transaction logging, similar to some
|
|
database systems.
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
Therefore, MARS can provide stronger consistency guarantees.
|
|
In case of network bottlenecks / problems / failures, the secondaries may
|
|
become outdated (reflect an elder state), but will not become inconsistent.
|
|
In contrast to DRBD, MARS preserves the order of write operations even
|
|
when the network is flaky (Anytime Consistency).
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
The current version of MARS supports k > 2 replicas and works asynchronously.
|
|
Therefore, application performance is completely decoupled from any network
|
|
problems.
|
|
Future versions are planned to also support synchronous or near-synchronous
|
|
modes.
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
MARS supports a new method for building Cloud Storage / Software Defined
|
|
Storage, called
|
|
\series bold
|
|
LV Football
|
|
\series default
|
|
.
|
|
It comes with some automation scripts, enabling a similar functionality
|
|
than Kubernetes, but devoted to stateful LVs over
|
|
\series bold
|
|
virtual LVM pools
|
|
\series default
|
|
in the petabytes range.
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
MARS is in production since 2014, and on thousands of Linux servers replicating
|
|
petabytes of data.
|
|
\end_layout
|
|
|
|
\end_body
|
|
\end_document
|