Angular Nx Tutorial - Step 10: Computation Caching

Nx has built-in computation caching, which helps drastically improve the performance of the commands.

To see it in action, run npx nx build todos:

> npx nx run todos:build
Generating ES5 bundles for differential loading...
ES5 bundle generation complete.

chunk {runtime} runtime-es2015.js, runtime-es2015.js.map (runtime) 6.16 kB [entry] [rendered]
chunk {runtime} runtime-es5.js, runtime-es5.js.map (runtime) 6.16 kB [entry] [rendered]
chunk {polyfills} polyfills-es2015.js, polyfills-es2015.js.map (polyfills) 141 kB [initial] [rendered]
chunk {main} main-es2015.js, main-es2015.js.map (main) 22.7 kB [initial] [rendered]
chunk {main} main-es5.js, main-es5.js.map (main) 24.1 kB [initial] [rendered]
chunk {styles} styles-es2015.js, styles-es2015.js.map (styles) 9.88 kB [initial] [rendered]
chunk {styles} styles-es5.js, styles-es5.js.map (styles) 11.1 kB [initial] [rendered]
chunk {polyfills-es5} polyfills-es5.js, polyfills-es5.js.map (polyfills-es5) 759 kB [initial] [rendered]
chunk {vendor} vendor-es2015.js, vendor-es2015.js.map (vendor) 2.35 MB [initial] [rendered]
chunk {vendor} vendor-es5.js, vendor-es5.js.map (vendor) 2.75 MB [initial] [rendered]

Now, run npx nx build todos again, and you will see the results appearing instantly:

> npx nx run todos:build

>  NX   NOTE  Cached Output:

Generating ES5 bundles for differential loading...
ES5 bundle generation complete.

chunk {polyfills-es5} polyfills-es5.js, polyfills-es5.js.map (polyfills-es5) 759 kB [initial] [rendered]
chunk {polyfills} polyfills-es2015.js, polyfills-es2015.js.map (polyfills) 141 kB [initial] [rendered]
chunk {main} main-es2015.js, main-es2015.js.map (main) 22.5 kB [initial] [rendered]
chunk {main} main-es5.js, main-es5.js.map (main) 23.9 kB [initial] [rendered]
chunk {vendor} vendor-es2015.js, vendor-es2015.js.map (vendor) 2.35 MB [initial] [rendered]
chunk {vendor} vendor-es5.js, vendor-es5.js.map (vendor) 2.75 MB [initial] [rendered]
chunk {styles} styles-es2015.js, styles-es2015.js.map (styles) 9.88 kB [initial] [rendered]
chunk {styles} styles-es5.js, styles-es5.js.map (styles) 11.1 kB [initial] [rendered]
chunk {runtime} runtime-es2015.js, runtime-es2015.js.map (runtime) 6.16 kB [entry] [rendered]
chunk {runtime} runtime-es5.js, runtime-es5.js.map (runtime) 6.16 kB [entry] [rendered]

Based on the state of the source code and the environment, Nx was able to figure out that it had already run this exact command. Nx found the artifact in the local cache and replayed the output and restored the necessary files.

Caching only works with the Nx CLI. Running ng build todos runs the command every single time.

Building multiple projects

Use the run-many command to rebuild the two applications:

1npx nx run-many --target=build --projects=todos,api

And notice the output:

Nx read the output from cache instead of running the command for 1 out of 2 projects.

Nx built api and retrieved todos from its computation cache. Read more about the cache here here.

Add --parallel to any command, and Nx does most of the work in parallel.

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