Commit graph

69 commits

Author SHA1 Message Date
Eelco Dolstra
eb3036da87 Implement querySubstitutablePathInfos() in the daemon
Also removed querySubstitutablePathInfo().
2012-07-11 10:43:24 -04:00
Eelco Dolstra
11800e6198 download-from-binary-cache: parallelise fetching of NAR info files
Getting substitute information using the binary cache substituter has
non-trivial latency overhead.  A package or NixOS system configuration
can have hundreds of dependencies, and in the worst case (when the
local info cache is empty) we have to do a separate HTTP request for
each of these.  If the ping time to the server is t, getting N info
files will take tN seconds; e.g., with a ping time of 0.1s to
nixos.org, sequentially downloading 1000 info files (a typical NixOS
config) will take at least 100 seconds.

To fix this problem, the binary cache substituter can now perform
requests in parallel.  This required changing the substituter
interface to support a function querySubstitutablePathInfos() that
queries multiple paths at the same time, and rewriting queryMissing()
to take advantage of parallelism.  (Due to local caching,
parallelising queryMissing() is sufficient for most use cases, since
it's almost always called before building a derivation and thus fills
the local info cache.)

For example, parallelism speeds up querying all 1056 paths in a
particular NixOS system configuration from 116s to 2.6s.  It works so
well because the eccentricity of the top-level derivation in the
dependency graph is only 9.  So we only need 10 round-trips (when
using an unlimited number of parallel connections) to get everything.

Currently we do a maximum of 150 parallel connections to the server.
Thus it's important that the binary cache server (e.g. nixos.org) has
a high connection limit.  Alternatively we could use HTTP pipelining,
but WWW::Curl doesn't support it and libcurl has a hard-coded limit of
5 requests per pipeline.
2012-07-06 19:08:20 -04:00
Eelco Dolstra
1aba0bf0fa nix-store -r: do substitutions in parallel
I.e. when multiple non-derivation arguments are passed to ‘nix-store
-r’ to be substituted, do them in parallel.
2012-06-27 16:58:15 -04:00
Eelco Dolstra
4bc4da331a Reserve some disk space for the garbage collector
We can't open a SQLite database if the disk is full.  Since this
prevents the garbage collector from running when it's most needed, we
reserve some dummy space that we can free just before doing a garbage
collection.  This actually revives some old code from the Berkeley DB
days.

Fixes #27.
2012-05-29 22:59:12 -04:00
Eelco Dolstra
117670be57 Make the garbage collector more concurrent
Make the garbage collector more concurrent by deleting valid paths
outside the region where we're holding the global GC lock.  This
should greatly reduce the time during which new builds are blocked,
since the deletion accounts for the vast majority of the time spent in
the GC.

To ensure that this is safe, the valid paths are invalidated and
renamed to some arbitrary path while we're holding the lock.  This
ensures that we when we finally delete the path, it's not a (newly)
valid or locked path.
2012-03-26 20:43:33 +02:00
Eelco Dolstra
194d21f9f6 * Sync with the trunk. 2011-12-16 23:33:01 +00:00
Eelco Dolstra
273b288a7e * importPath() -> importPaths(). Because of buffering of the input
stream it's now necessary for the daemon to process the entire
  sequence of exported paths, rather than letting the client do it.
2011-12-16 22:31:25 +00:00
Shea Levy
af2e53fd48 Include all outputs of derivations in the closure of explicitly-passed derivation paths
This required adding a queryOutputDerivationNames function in the store API
2011-11-06 06:28:20 +00:00
Eelco Dolstra
13114daa3e * Ouch. A store upgrade could cause a substituter to be triggered,
causing a deadlock.
2011-09-12 09:07:43 +00:00
Eelco Dolstra
b2027f70d9 * Fix a huuuuge security hole in the Nix daemon. It didn't check that
derivations added to the store by clients have "correct" output
  paths (meaning that the output paths are computed by hashing the
  derivation according to a certain algorithm).  This means that a
  malicious user could craft a special .drv file to build *any*
  desired path in the store with any desired contents (so long as the
  path doesn't already exist).  Then the attacker just needs to wait
  for a victim to come along and install the compromised path.

  For instance, if Alice (the attacker) knows that the latest Firefox
  derivation in Nixpkgs produces the path

    /nix/store/1a5nyfd4ajxbyy97r1fslhgrv70gj8a7-firefox-5.0.1

  then (provided this path doesn't already exist) she can craft a .drv
  file that creates that path (i.e., has it as one of its outputs),
  add it to the store using "nix-store --add", and build it with
  "nix-store -r".  So the fake .drv could write a Trojan to the
  Firefox path.  Then, if user Bob (the victim) comes along and does

    $ nix-env -i firefox
    $ firefox

  he executes the Trojan injected by Alice.

  The fix is to have the Nix daemon verify that derivation outputs are
  correct (in addValidPath()).  This required some refactoring to move
  the hash computation code to libstore.
2011-07-20 18:10:47 +00:00
Eelco Dolstra
8062d3af30 * `nix-store --verify --check-contents': don't hold the global GC lock
while checking the contents, since this operation can take a very
  long time to finish.  Also, fill in missing narSize fields in the DB
  while doing this.
2010-12-06 15:29:38 +00:00
Eelco Dolstra
e60c962fb8 * Add an operation `nix-store -q --size'. 2010-11-17 12:40:52 +00:00
Eelco Dolstra
a3883cbd28 * Store the size of a store path in the database (to be precise, the
size of the NAR serialisation of the path, i.e., `nix-store --dump
  PATH').  This is useful for Hydra.
2010-11-16 17:11:46 +00:00
Eelco Dolstra
e2e168f7c2 `nix-store --verify' improvements:
* If a path has disappeared, check its referrers first, and don't try
  to invalidate paths that have valid referrers.  Otherwise we get a
  foreign key constraint violation.
* Read the whole Nix store directory instead of statting each valid
  path, which is slower.
* Acquire the global GC lock.
2010-08-31 11:47:31 +00:00
Eelco Dolstra
3e5e0faf9c * Okay, putting a lock on the temporary directory used by importPath()
doesn't work because the garbage collector doesn't actually look at
  locks.  So r22253 was stupid.  Use addTempRoot() instead.  Also,
  locking the temporary directory in exportPath() was silly because it
  isn't even in the store.
2010-06-21 11:08:09 +00:00
Eelco Dolstra
f92c9a0ac5 * Allow unprivileged users to do `nix-store --clear-failed-paths' and
`nix-store --query-failed-paths'.
2010-05-04 10:45:10 +00:00
Eelco Dolstra
6199f9b93e * Added a command `nix-store --clear-failed-paths <PATHS>' to clear
the "failed" status of the given store paths.  The special value `*'
  clears all failed paths.
2010-04-26 12:56:42 +00:00
Eelco Dolstra
2398af13c5 * Add an command `nix-store --query-failed-paths' to list the cached
failed paths (when using the `build-cache-failure' option).
2010-04-26 12:43:42 +00:00
Eelco Dolstra
e33f67ff0b * Refactor the upgrade / database initialisation logic a bit. 2010-02-24 16:30:20 +00:00
Eelco Dolstra
cfe742cfc5 * A function to query just the database id of a valid path. 2010-02-24 15:07:23 +00:00
Eelco Dolstra
a3c63d0d6c * Disable fsync() in SQLite if the fsync-metadata option is set to
false.
* Change the default for `fsync-metadata' to true.
* Disable `fsync-metadata' in `make check'.
2010-02-24 13:12:57 +00:00
Eelco Dolstra
c4d388add4 * Get derivation outputs from the database instead of the .drv file,
which requires more I/O.
2010-02-22 12:44:36 +00:00
Eelco Dolstra
103cfee056 * Revert r19650 (implement gc-keep-outputs by looking for derivations
with the same name as the output) and instead use the
  DerivationOutputs table in the database, which is the correct way to
  to do things.
2010-02-22 11:44:17 +00:00
Eelco Dolstra
299ff64812 * Put the derivation outputs in the database. This is useful for the
garbage collector.
2010-02-22 11:15:50 +00:00
Eelco Dolstra
1930570ad9 * Foreign key support in SQLite is not a persistent setting, so enable
it at startup.
* Implement negative caching.  Now `make check' passes.
2010-02-19 17:15:22 +00:00
Eelco Dolstra
9c9a88e9e2 * Implement more stuff. 2010-02-19 16:43:25 +00:00
Eelco Dolstra
762cee72cc * Implement registerValidPath(). 2010-02-19 16:04:51 +00:00
Eelco Dolstra
836e5b6f57 * Implemented queryReferrers(). 2010-02-18 16:21:59 +00:00
Eelco Dolstra
77cb9e3fb1 * Implement queryPathInfo(). 2010-02-18 15:52:57 +00:00
Eelco Dolstra
885e22b16e * Implement isValidPath(). 2010-02-18 15:11:08 +00:00
Eelco Dolstra
e0305bb7a8 * Some wrapper objects to ensure that SQLite objects are properly
destroyed.
2010-02-18 14:30:42 +00:00
Eelco Dolstra
c1a07f9445 * Convert the Nix database to SQLite. 2010-02-18 13:16:59 +00:00
Eelco Dolstra
07ffdc2862 * Added an option "fsync-metadata" to fsync() changes to
/nix/var/nix/db.
* Removed the function writeStringToFile since it does (almost) the
  same thing as writeFile.
2010-01-29 12:22:58 +00:00
Eelco Dolstra
5388944e8d * Make the garbage collector do the right thing when `gc-keep-outputs'
is enabled by not depending on the deriver.
2010-01-25 16:04:32 +00:00
Eelco Dolstra
c364d5d1e3 * Made the garbage collector a lot faster. It no longer computes the
complete set of live and dead paths before starting the actual
  deletion, but determines liveness on demand.  I.e. for any path in
  the store, it first tries to delete all the referrers, and then the
  path itself.  This means that the collector can start deleting paths
  almost immediately.
2009-11-23 16:34:24 +00:00
Eelco Dolstra
6b9f6b0222 * Remove a prototype for a function that no longer exists. 2009-10-22 08:12:38 +00:00
Eelco Dolstra
14bc3ce3d6 * Canonicalise timestamps in the Nix store to 1 (1970-01-01 00:00:01
UTC) rather than 0 (00:00:00).  1 is a better choice because some
  programs use 0 as a special value.  For instance, the Template
  Toolkit uses a timestamp of 0 to denote the non-existence of a file,
  so it barfs on files in the Nix store (see
  template-toolkit-nix-store.patch in Nixpkgs).  Similarly, Maya 2008
  fails to load script directories with a timestamp of 0 and can't be
  patched because it's closed source.

  This will also shut up those "implausibly old time stamp" GNU tar
  warnings.
2009-06-13 16:30:58 +00:00
Eelco Dolstra
c7152c8f97 * Don't use the non-standard __gnu_cxx::stdio_filebuf class. 2009-03-28 19:41:53 +00:00
Eelco Dolstra
92f525ecf4 * Negative caching, i.e. caching of build failures. Disabled by
default.  This is mostly useful for Hydra.
2009-03-25 21:05:42 +00:00
Eelco Dolstra
8fce03e0ad * nix-store --verify: repair bad hash fields in the metadata file. 2008-12-16 13:28:18 +00:00
Eelco Dolstra
82ae85de27 * addToStore() in nix-worker: don't write the NAR dump received from
the client to a temporary directory, as that is highly inefficient.
2008-12-03 18:05:14 +00:00
Eelco Dolstra
ff762fb499 * Pass HashType values instead of strings. 2008-12-03 16:10:17 +00:00
Eelco Dolstra
64519cfd65 * Unify the treatment of sources copied to the store, and recursive
SHA-256 outputs of fixed-output derivations.  I.e. they now produce
  the same store path:

  $ nix-store --add x
  /nix/store/j2fq9qxvvxgqymvpszhs773ncci45xsj-x

  $ nix-store --add-fixed --recursive sha256 x
  /nix/store/j2fq9qxvvxgqymvpszhs773ncci45xsj-x

  the latter being the same as the path that a derivation

    derivation {
      name = "x";
      outputHashAlgo = "sha256";
      outputHashMode = "recursive";
      outputHash = "...";
      ...
    };

  produces.

  This does change the output path for such fixed-output derivations.
  Fortunately they are quite rare.  The most common use is fetchsvn
  calls with SHA-256 hashes.  (There are a handful of those is
  Nixpkgs, mostly unstable development packages.)
  
* Documented the computation of store paths (in store-api.cc).
2008-12-03 15:06:30 +00:00
Eelco Dolstra
c987061aa4 * Some refactoring. Better output with `-v' for --use-atime. 2008-09-17 12:54:07 +00:00
Eelco Dolstra
7ab68961e4 * Garbage collector: added an option `--use-atime' to delete paths in
order of ascending last access time.  This is useful in conjunction
  with --max-freed or --max-links to prefer deleting non-recently used
  garbage, which is good (especially in the build farm) since garbage
  may become live again.

  The code could easily be modified to accept other criteria for
  ordering garbage by changing the comparison operator used by the
  priority queue in collectGarbage().
2008-09-17 10:02:55 +00:00
Eelco Dolstra
5adbb0aabe * build.cc: only use a substituter if it returns info for a path. 2008-08-04 13:15:35 +00:00
Eelco Dolstra
3c92ea399d * Make nix-env --dry-run print the paths to be substituted correctly
again.  (After the previous substituter mechanism refactoring I
  didn't update the code that obtains the references of substitutable
  paths.)  This required some refactoring: the substituter programs
  are now kept running and receive/respond to info requests via
  stdin/stdout.
2008-08-02 12:54:35 +00:00
Eelco Dolstra
a72709afd8 * Some refactoring: put the GC options / results in separate structs.
* The garbage collector now also prints the number of blocks freed.
2008-06-18 09:34:17 +00:00
Eelco Dolstra
826b271d9a * Garbage collector: don't do a complete topological sort of the Nix
store under the reference relation, since that means that the
  garbage collector will need a long time to start deleting paths.
  Instead just delete the referrers of a path first.
2008-06-13 18:25:24 +00:00
Eelco Dolstra
b0e92f6d47 * Merged the no-bdb branch (-r10900:HEAD
https://svn.nixos.org/repos/nix/nix/branches/no-bdb).
2008-06-09 13:52:45 +00:00