Merge pull request #379 from hibell/create-scc

Build server and app shared class cache

buildpack.toml

@@ -93,6 +93,34 @@ api = "0.7"
     launch = false
     name = "BP_LIBERTY_FEATURE_INSTALL_DISABLED"
 
+  [[metadata.configurations]]
+    build = true
+    default = "false"
+    description = "OpenJ9 only: Disable building the shared class cache."
+    launch = false
+    name = "BP_LIBERTY_SCC_DISABLED"
+
+  [[metadata.configurations]]
+    build = true
+    default = "100"
+    description = "OpenJ9 only: Size to use for the shared class cache."
+    launch = false
+    name = "BP_LIBERTY_SCC_SIZE_MB"
+
+  [[metadata.configurations]]
+    build = true
+    default = "1"
+    description = "OpenJ9 only: Number of iterations to cycle the server when building the shared class cache."
+    launch = false
+    name = "BP_LIBERTY_SCC_NUM_ITERATIONS"
+
+  [[metadata.configurations]]
+    build = true
+    default = "false"
+    description = "OpenJ9 only: Disable trimming the size of the shared class cache."
+    launch = false
+    name = "BP_LIBERTY_SCC_TRIM_SIZE_DISABLED"
+
   [[metadata.dependencies]]
     cpes = ["cpe:2.3:a:ibm:open_liberty:23.0.0.2:*:*:*:*:*:*:*"]
     id = "open-liberty-runtime-full"

internal/util/jvm.go

@@ -19,11 +19,18 @@ package util
 import (
 	"bufio"
 	"bytes"
+	"errors"
 	"fmt"
+	"github.com/paketo-buildpacks/libpak/bard"
 	"github.com/paketo-buildpacks/libpak/effect"
+	"io"
+	"os/exec"
+	"regexp"
+	"strconv"
 	"strings"
 )
 
+// DetectJVMName returns the value for java.vm.name.
 func DetectJVMName(executor effect.Executor) (string, error) {
 	buf := &bytes.Buffer{}
 
@@ -47,5 +54,115 @@ func DetectJVMName(executor effect.Executor) (string, error) {
 			break
 		}
 	}
+
+	if err := scanner.Err(); err != nil {
+		return "", fmt.Errorf("unable to read JVM name\n%w", err)
+	}
+
 	return "", nil
 }
+
+type SharedClassCache struct {
+	Name string
+	Path string
+
+	Executor effect.Executor
+	Logger   bard.Logger
+}
+
+type SharedClassCacheOptions struct {
+	Enabled       bool
+	SizeMB        int
+	NumIterations int
+	Trim          bool
+}
+
+func (scc SharedClassCache) GetFillRatio() (float64, error) {
+	sccOption := fmt.Sprintf("-Xshareclasses:name=%s,cacheDir=%s,printTopLayerStats", scc.Name, scc.Path)
+	args := []string{sccOption, "-version"}
+	buf := &bytes.Buffer{}
+	stderrBuf := &bytes.Buffer{}
+	err := scc.Executor.Execute(effect.Execution{
+		Command: "java",
+		Args:    args,
+		Stdout:  buf,
+		Stderr:  stderrBuf,
+	})
+	var exitError *exec.ExitError
+	if errors.As(err, &exitError) && exitError.ExitCode() != 1 {
+		return 0.0, fmt.Errorf("unable to get cache stats\n%w\n%s", err, stderrBuf.String())
+	}
+
+	r := regexp.MustCompile(`Cache is (\d+)% full`)
+
+	scanner := bufio.NewScanner(buf)
+	for scanner.Scan() {
+		line := scanner.Text()
+		scc.Logger.Debugf("%s\n", line)
+		if matches := r.FindStringSubmatch(line); matches != nil {
+			v, err := strconv.ParseInt(matches[1], 10, 64)
+			if err != nil {
+				return 0.0, fmt.Errorf("unable to parse [%s] to int\n%w", matches[1], err)
+			}
+			return float64(v) / 100, nil
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return 0.0, fmt.Errorf("unable to read cache ratio\n%w", err)
+	}
+
+	return 0.0, fmt.Errorf("unable to find cache fill ratio")
+}
+
+func (scc SharedClassCache) CreateLayer(size int) error {
+	scc.Logger.Bodyf("Creating SCC layer with size %dm", size)
+	return scc.execSccCommand("createLayer,groupAccess", fmt.Sprintf("-Xscmx%dm", size))
+}
+
+func (scc SharedClassCache) Resize(size int) error {
+	fillRatio, err := scc.GetFillRatio()
+	if err != nil {
+		return err
+	}
+	newSize := int(float64(size)*fillRatio + 0.5)
+	scc.Logger.Bodyf("Resizing cache from %dm to %dm", size, newSize)
+	if err := scc.Delete(); err != nil {
+		return err
+	}
+	if err := scc.CreateLayer(newSize); err != nil {
+		return fmt.Errorf("unable to create resized layer\n%w", err)
+	}
+	return nil
+}
+
+func (scc SharedClassCache) Delete() error {
+	err := scc.execSccCommand("destroy")
+	var exitError *exec.ExitError
+	if errors.As(err, &exitError) && exitError.ExitCode() == 1 {
+		return nil
+	}
+	if err != nil {
+		return fmt.Errorf("unable to destroy cache\n%w", err)
+	}
+	return nil
+}
+
+func (scc SharedClassCache) execSccCommand(command string, options ...string) error {
+	sccOption := fmt.Sprintf("-Xshareclasses:name=%s,cacheDir=%s,%s", scc.Name, scc.Path, command)
+	writer := io.Discard
+	if scc.Logger.IsDebugEnabled() {
+		sccOption = fmt.Sprintf("%s,verbose", sccOption)
+		writer = scc.Logger.InfoWriter()
+	}
+	args := []string{sccOption}
+	if options != nil {
+		args = append(args, options...)
+	}
+	return scc.Executor.Execute(effect.Execution{
+		Command: "java",
+		Args:    append(args, "-version"),
+		Stdout:  writer,
+		Stderr:  writer,
+	})
+}

liberty/build.go

@@ -21,6 +21,7 @@ import (
 	"github.com/paketo-buildpacks/liberty/internal/util"
 	"github.com/paketo-buildpacks/libpak/bindings"
 	"github.com/paketo-buildpacks/libpak/sherpa"
+	"strconv"
 	"strings"
 
 	"github.com/buildpacks/libcnb"
@@ -215,6 +216,10 @@ func (b Build) Build(context libcnb.BuildContext) (libcnb.BuildResult, error) {
 	result.Layers = append(result.Layers, base)
 
 	if installType == openLibertyInstall || installType == websphereLibertyInstall {
+		sccOptions, err := getSharedClassOptions(cr, jvmName)
+		if err != nil {
+			return libcnb.BuildResult{}, fmt.Errorf("unable to get SCC options\n%w", err)
+		}
 		if err := b.buildDistributionRuntime(
 			profile,
 			version,
@@ -224,6 +229,7 @@ func (b Build) Build(context libcnb.BuildContext) (libcnb.BuildResult, error) {
 			disableFeatureInstall,
 			featureList,
 			detectedBuildSrc,
+			sccOptions,
 			dr,
 			dc,
 			&result); err != nil {
@@ -240,6 +246,32 @@ func (b Build) Build(context libcnb.BuildContext) (libcnb.BuildResult, error) {
 	return result, nil
 }
 
+func getSharedClassOptions(cr libpak.ConfigurationResolver, jvmName string) (util.SharedClassCacheOptions, error) {
+	if jvmName != "OpenJ9" {
+		return util.SharedClassCacheOptions{
+			Enabled: false,
+		}, nil
+	}
+
+	resolvedSize, _ := cr.Resolve("BP_LIBERTY_SCC_SIZE_MB")
+	size, err := strconv.Atoi(resolvedSize)
+	if err != nil {
+		return util.SharedClassCacheOptions{}, fmt.Errorf("unable to parse BP_LIBERTY_SCC_SIZE_MB\n%w", err)
+	}
+	resolvedNumIterations, _ := cr.Resolve("BP_LIBERTY_SCC_NUM_ITERATIONS")
+	numIterations, err := strconv.Atoi(resolvedNumIterations)
+	if err != nil {
+		return util.SharedClassCacheOptions{}, fmt.Errorf("unable to parse BP_LIBERTY_SCC_NUM_ITERATIONS\n%w", err)
+	}
+
+	return util.SharedClassCacheOptions{
+		Enabled:       !cr.ResolveBool("BP_LIBERTY_SCC_DISABLED"),
+		SizeMB:        size,
+		NumIterations: numIterations,
+		Trim:          !cr.ResolveBool("BP_LIBERTY_SCC_TRIM_SIZE_DISABLED"),
+	}, nil
+}
+
 func (b Build) buildDistributionRuntime(
 	profile string,
 	version string,
@@ -249,6 +281,7 @@ func (b Build) buildDistributionRuntime(
 	disableFeatureInstall bool,
 	features []string,
 	buildSrc core.BuildSource,
+	sccOptions util.SharedClassCacheOptions,
 	dependencyResolver libpak.DependencyResolver,
 	cache libpak.DependencyCache,
 	result *libcnb.BuildResult) error {
@@ -272,7 +305,7 @@ func (b Build) buildDistributionRuntime(
 		return fmt.Errorf("unable to load iFixes\n%w", err)
 	}
 
-	distro := NewDistribution(dep, cache, installType, serverName, appPath, disableFeatureInstall, features, iFixes, b.Executor)
+	distro := NewDistribution(dep, cache, installType, serverName, appPath, disableFeatureInstall, features, iFixes, sccOptions, b.Executor)
 	distro.Logger = b.Logger
 
 	result.Layers = append(result.Layers, distro)

liberty/build_test.go

@@ -55,6 +55,10 @@ func testBuild(t *testing.T, context spec.G, it spec.S) {
 				{"name": "BP_LIBERTY_PROFILE", "default": "", "build": true},
 				{"name": "BP_LIBERTY_INSTALL_TYPE", "default": "ol", "build": true},
 				{"name": "BP_LIBERTY_SERVER_NAME", "default": "", "build": true},
+				{"name": "BP_LIBERTY_SCC_DISABLED", "default": "false", "build": true},
+				{"name": "BP_LIBERTY_SCC_SIZE_MB", "default": "100", "build": true},
+				{"name": "BP_LIBERTY_SCC_NUM_ITERATIONS", "default": "1", "build": true},
+				{"name": "BP_LIBERTY_SCC_TRIM_SIZE_DISABLED", "default": "false", "build": true},
 			},
 			"dependencies": []map[string]interface{}{
 				{"id": "open-liberty-runtime-kernel", "version": "21.0.11"},