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doc_reformat_performance.txt

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- Added heading format begining and ending by "=="
   - Added Index
   - Added Title
        
   Note: No change are made in paragraphs content
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freestorm77 2010-04-24 04:44:44 -07:00
parent 6f224ad1fd
commit be5604f0e0
1 changed files with 23 additions and 11 deletions
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docs/performance.txt
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@ -1,6 +1,18 @@
= Performance costs for some common operations =
=== Publishing an A-byte immutable file ===
1. Publishing an A-byte immutable file
2. Publishing an A-byte mutable file
3. Downloading B bytes of an A-byte immutable file
4. Downloading B bytes of an A-byte mutable file
5. Modifying B bytes of an A-byte mutable file
6. Inserting/Removing B bytes in an A-byte mutable file
7. Adding an entry to an A-entry directory
8. Listing an A entry directory
9. Performing a file-check on an A-byte file
10. Performing a file-verify on an A-byte file
11. Repairing an A-byte file (mutable or immutable)
== Publishing an A-byte immutable file ==
network: A
memory footprint: N/k*128KiB
@ -10,7 +22,7 @@ notes: An immutable file upload requires an additional I/O pass over the entire
encryption derives the encryption key in part from the contents of the
source file.
=== Publishing an A-byte mutable file ===
== Publishing an A-byte mutable file ==
network: A
memory footprint: N/k*A
@ -26,7 +38,7 @@ notes: Tahoe-LAFS generates a new RSA keypair for each mutable file that
Tahoe-LAFS to have an unacceptably large memory footprint (at
least when uploading a mutable file).
=== Downloading B bytes of an A-byte immutable file ===
== Downloading B bytes of an A-byte immutable file ==
network: A
memory footprint: 128KiB
@ -48,7 +60,7 @@ notes: When asked to read an arbitrary range of an immutable file,
to read, what part of the file was read by previous reads, and
how much time has elapsed since the last read.
=== Downloading B bytes of an A-byte mutable file ===
== Downloading B bytes of an A-byte mutable file ==
network: A
memory footprint: A
@ -57,7 +69,7 @@ notes: As currently implemented, mutable files must be downloaded in
their entirety before any part of them can be read. We are
exploring fixes for this; see ticket #393 for more information.
=== Modifying B bytes of an A-byte mutable file ===
== Modifying B bytes of an A-byte mutable file ==
network: A
memory footprint: N/k*A
@ -70,7 +82,7 @@ notes: If you upload a changed version of a mutable file that you
essentially uploading the file over again, except that it re-uses
the existing RSA keypair instead of generating a new one.
=== Inserting/Removing B bytes in an A-byte mutable file ===
== Inserting/Removing B bytes in an A-byte mutable file ==
network: A
memory footprint: N/k*A
@ -85,7 +97,7 @@ notes: Modifying any part of a mutable file in Tahoe-LAFS requires that
be modified, as described in "Modifying B bytes of an A-byte mutable
file".
=== Adding an entry to an A-entry directory ===
== Adding an entry to an A-entry directory ==
network: O(A)
memory footprint: N/k*A
@ -94,7 +106,7 @@ notes: In Tahoe-LAFS, directories are implemented as specialized mutable
files. So adding an entry to a directory is essentially adding B
(actually, 300-330) bytes somewhere in an existing mutable file.
=== Listing an A entry directory ===
== Listing an A entry directory ==
network: O(A)
memory footprint: N/k*A
@ -104,7 +116,7 @@ notes: Listing a directory requires that the mutable file storing the
directory requires downloading a (roughly) 330 * A byte mutable
file, since each directory entry is about 300-330 bytes in size.
=== Performing a file-check on an A-byte file ===
== Performing a file-check on an A-byte file ==
network: O(S), where S is the number of servers on your grid
memory footprint: negligible
@ -114,7 +126,7 @@ notes: To check a file, Tahoe-LAFS queries all the servers that it knows
of the file. This is relatively inexpensive, compared to the verify
and repair operations.
=== Performing a file-verify on an A-byte file ===
== Performing a file-verify on an A-byte file ==
network: N/k*A
memory footprint: N/k*128KiB
@ -125,7 +137,7 @@ notes: To verify a file, Tahoe-LAFS downloads all of the ciphertext
expensive than downloading an A-byte file, since only a fraction
of these shares are necessary to recover the file.
=== Repairing an A-byte file (mutable or immutable) ===
== Repairing an A-byte file (mutable or immutable) ==
network: variable; up to around O(A)
memory footprint: from 128KiB to (1+N/k)*128KiB