When running in parallel mode, worker processes forward errors thrown
during task processing to the master process, which in turn exits with
an error.
However, there are cases where the error is not directly related to
processing the entry-point. One such case is when there is not enough
memory (for example, due to all the other tasks being processed
simultaneously).
Previously, an `ENOMEM` error thrown on a worker process would propagate
to the master process, eventually causing ngcc to exit with an error.
Example failure: https://circleci.com/gh/angular/angular/682198
This commit improves handling of these low-memory situations by
detecting `ENOMEM` errors and killing the worker process, thus allowing
the master process to decide how to handle that. The master process will
put the task back into the tasks queue and continue processing tasks
with the rest of the worker processes (and thus with lower memory
pressure).
PR Close#36626
Previously, when running in parallel mode and a worker process crashed
while processing a task, it was not possible for ngcc to continue
without risking ending up with a corrupted entry-point and therefore it
exited with an error. This, for example, could happen when a worker
process received a `SIGKILL` signal, which was frequently observed in CI
environments. This was probably the result of Docker killing processes
due to increased memory pressure.
One factor that amplifies the problem under Docker (which is often used
in CI) is that it is not possible to distinguish between the available
CPU cores on the host machine and the ones made available to Docker
containers, thus resulting in ngcc spawning too many worker processes.
This commit addresses these issues in the following ways:
1. We take advantage of the fact that files are written to disk only
after an entry-point has been fully analyzed/compiled. The master
process can now determine whether a worker process has not yet
started writing files to disk (even if it was in the middle of
processing a task) and just put the task back into the tasks queue if
the worker process crashes.
2. The master process keeps track of the transformed files that a worker
process will attempt to write to disk. If the worker process crashes
while writing files, the master process can revert any changes and
put the task back into the tasks queue (without risking corruption).
3. When a worker process crashes while processing a task (which can be a
result of increased memory pressure or too many worker processes),
the master process will not try to re-spawn it. This way the number
or worker processes is gradually adjusted to a level that can be
accomodated by the system's resources.
Examples of ngcc being able to recover after a worker process crashed:
- While idling: https://circleci.com/gh/angular/angular/682197
- While compiling: https://circleci.com/gh/angular/angular/682209
- While writing files: https://circleci.com/gh/angular/angular/682267
Jira issue: [FW-2008](https://angular-team.atlassian.net/browse/FW-2008)
Fixes#36278
PR Close#36626
With this commit, worker processes will notify the master process about
the transformed files they are about to write to disk before starting
writing them.
In a subsequent commit, this will be used to allow ngcc to recover when
a worker process crashes in the middle of processing a task.
PR Close#36626
This commit enhances the `CompileFn`, which is used to process each
entry-point, to support running a passed-in callback (and wait for it to
complete) before proceeding with writing the transformed files to disk.
This functionality is currently not used. In a subsequent commit, it
will be used for passing info from worker processes to the master
process that will allow ngcc to recover when a worker process crashes in
the middle of processing a task.
PR Close#36626
The current ngcc lock-file strategy spawns a new process in order to
capture a potential `SIGINT` and remove the lock-file. For more
information see #35861.
Previously, this unlocker process was spawned as soon as the `LockFile`
was instantiated in order to have it available as soon as possible
(given that spawning a process is an asynchronous operation). Since the
`LockFile` was instantiated and passed to the `Executor`, this meant
that an unlocker process was spawned for each cluster worker, when
running ngcc in parallel mode. These processes were not needed, since
the `LockFile` was not used in cluster workers, but we still had to pay
the overhead of each process' own memory and V8 instance.
(NOTE: This overhead was small compared to the memory consumed by ngcc's
normal operations, but still unnecessary.)
This commit avoids the extra processes by only spawning an unlocker
process when running on the cluster master process and not on worker
processes.
PR Close#36569
1. update jasmine to 3.5
2. update @types/jasmine to 3.5
3. update @types/jasminewd2 to 2.0.8
Also fix several cases, the new jasmine 3 will help to create test cases correctly,
such as in the `jasmine 2.x` version, the following case will pass
```
expect(1 == 2);
```
But in jsamine 3, the case will need to be
```
expect(1 == 2).toBeTrue();
```
PR Close#34625
Moving the definition of the `onTaskCompleted` callback into `mainNgcc()`
allows it to be configured based on options passed in there more easily.
This will be the case when we want to configure whether to log or throw
an error for tasks that failed to be processed successfully.
This commit also creates two new folders and moves the code around a bit
to make it easier to navigate the code§:
* `execution/tasks`: specific helpers such as task completion handlers
* `execution/tasks/queues`: the `TaskQueue` implementations and helpers
PR Close#36083
The previous implementation mixed up the management
of locking a piece of code (both sync and async) with the
management of writing and removing the lockFile that is
used as the flag for which process has locked the code.
This change splits these two concepts up. Apart from
avoiding the awkward base class it allows the `LockFile`
implementation to be replaced cleanly.
PR Close#35861
ngcc uses a lockfile to prevent two ngcc instances from executing at the
same time. Previously, if a lockfile was found the current process would
error and exit.
Now, when in async mode, the current process is able to wait for the previous
process to release the lockfile before continuing itself.
PR Close#35131
Ngcc adds properties to the `package.json` files of the entry-points it
processes to mark them as processed for a format and point to the
created Ivy entry-points (in case of `--create-ivy-entry-points`). When
running ngcc in parallel mode (which is the default for the standalone
ngcc command), multiple formats can be processed simultaneously for the
same entry-point and the order of completion is not deterministic.
Previously, ngcc would append new properties at the end of the target
object in `package.json` as soon as the format processing was completed.
As a result, the order of properties in the resulting `package.json`
(when processing multiple formats for an entry-point in parallel) was
not deterministic. For tools that use file hashes for caching purposes
(such as Bazel), this lead to a high probability of cache misses.
This commit fixes the problem by ensuring that the position of
properties added to `package.json` files is deterministic and
independent of the order in which each format is processed.
Jira issue: [FW-1801](https://angular-team.atlassian.net/browse/FW-1801)
Fixes#34635
PR Close#34870
Previously, it was possible for multiple instance of ngcc to be running
at the same time, but this is not supported and can cause confusing and
flakey errors at build time.
Now, only one instance of ngcc can run at a time. If a second instance
tries to execute it fails with an appropriate error message.
See https://github.com/angular/angular/issues/32431#issuecomment-571825781
PR Close#34722
`ngcc` supports both synchronous and asynchronous execution. The default
mode when using `ngcc` programmatically (which is how `@angular/cli` is
using it) is synchronous. When running `ngcc` from the command line
(i.e. via the `ivy-ngcc` script), it runs in async mode.
Previously, the work would be executed in the same way in both modes.
This commit improves the performance of `ngcc` in async mode by
processing tasks in parallel on multiple processes. It uses the Node.js
built-in [`cluster` module](https://nodejs.org/api/cluster.html) to
launch a cluster of Node.js processes and take advantage of multi-core
systems.
Preliminary comparisons indicate a 1.8x to 2.6x speed improvement when
processing the angular.io app (apparently depending on the OS, number of
available cores, system load, etc.). Further investigation is needed to
better understand these numbers and identify potential areas of
improvement.
Inspired by/Based on @alxhub's prototype: alxhub/angular@cb631bdb1
Original design doc: https://hackmd.io/uYG9CJrFQZ-6FtKqpnYJAA?view
Jira issue: [FW-1460](https://angular-team.atlassian.net/browse/FW-1460)
PR Close#32427
George Kalpakas
Pete Bacon Darwin
JiaLiPassion
Alan Agius