Chapter 3. Red Hat build of OpenJDK features

The latest Red Hat build of OpenJDK 17 release might include new features. Additionally, the latest release might enhance, deprecate, or remove features that originated from previous Red Hat build of OpenJDK 17 releases.

Note

For all the other changes and security fixes, see OpenJDK 17.0.10 Released.

Red Hat build of OpenJDK enhancements

Red Hat build of OpenJDK 17 provides enhancements to features originally created in previous releases of Red Hat build of OpenJDK.

KEEPALIVE extended socket options support added on Windows

On Windows 10 version 1709 or later platforms, the java.net.ExtendedSocketOptions class now supports the TCP_KEEPIDLE and TCP_KEEPINTERVAL options.

Similarly, on Windows 10 version 1703 or later platforms, the java.net.ExtendedSocketOptions class now supports the TCP_KEEPCOUNT option.

See JDK-8308593 (JDK Bug System).

X509KeyManager.chooseClientAlias method called once for all key types

In Red Hat build of OpenJDK 17.0.10, TLS or Datagram TLS (DTLS) now makes only one call to the X509KeyManager.chooseClientAlias method during handshakes for client authentication, regardless of how many algorithms are requested.

See JDK-8262186 (JDK Bug System).

Peak values for committed memory included in NMT reports

In Red Hat build of OpenJDK 17.0.10, Native Memory Tracking (NMT) reports now show the peak value for all categories. The peak value is the highest value for committed memory in a given NMT category over the lifetime of the JVM process.

If the committed memory for a category is currently at its highest value, the NMT report shows an at peak value; otherwise, the NMT report shows the historic peak value.

For example, the following report output shows that compiler arena memory peaked above 6 MB but is now approximately 200KB:

Compiler (arena=196KB #4) (peak=6126KB #16)

See JDK-8317772 (JDK Bug System).

JVM warnings about unsupported THPs on Red Hat Enterprise Linux

On Red Hat Enterprise Linux platforms, if Transparent Huge Pages (THPs) are requested but not supported, the JVM now prints the following message to standard output:

UseTransparentHugePages disabled; transparent huge pages are not supported by the operating system.

See JDK-8313782 (JDK Bug System).

Increased default value of jdk.jar.maxSignatureFileSize system property

Red Hat build of OpenJDK 17.0.8 introduced a jdk.jar.maxSignatureFileSize system property for configuring the maximum number of bytes that are allowed for the signature-related files in a Java archive (JAR) file (JDK-8300596). By default, the jdk.jar.maxSignatureFileSize property was set to 8000000 bytes (8 MB), which was too small for some JAR files, such as the Mend (formerly WhiteSource) Unified Agent JAR file.

Red Hat build of OpenJDK 17.0.10 increases the default value of the jdk.jar.maxSignatureFileSize property to 16000000 bytes (16 MB).

See JDK-8312489 (JDK Bug System)

Let’s Encrypt ISRG Root X2 CA certificate added

In Red Hat build of OpenJDK 17.0.10, the cacerts truststore includes the Internet Security Research Group (ISRG) Root X2 certificate authority (CA) certificate from Let’s Encrypt:

  • Name: Let’s Encrypt
  • Alias name: letsencryptisrgx2
  • Distinguished name: CN=ISRG Root X2, O=Internet Security Research Group, C=US

See JDK-8317374 (JDK Bug System).

Digicert, Inc. root certificates added

In Red Hat build of OpenJDK 17.0.10, the cacerts truststore includes four Digicert, Inc. root certificates:

Certificate 1
  • Name: DigiCert, Inc.
  • Alias name: digicertcseccrootg5
  • Distinguished name: CN=DigiCert CS ECC P384 Root G5, O="DigiCert, Inc.", C=US
Certificate 2
  • Name: DigiCert, Inc.
  • Alias name: digicertcsrsarootg5
  • Distinguished name: CN=DigiCert CS RSA4096 Root G5, O="DigiCert, Inc.", C=US
Certificate 3
  • Name: DigiCert, Inc.
  • Alias name: digicerttlseccrootg5
  • Distinguished name: CN=DigiCert TLS ECC P384 Root G5, O="DigiCert, Inc.", C=US
Certificate 4
  • Name: DigiCert, Inc.
  • Alias name: digicerttlsrsarootg5
  • Distinguished name: CN=DigiCert TLS RSA4096 Root G5, O="DigiCert, Inc.", C=US

See JDK-8318759 (JDK Bug System).

eMudhra Technologies Limited root certificates added

In Red Hat build of OpenJDK 17.0.10, the cacerts truststore includes three eMudhra Technologies Limited root certificates:

Certificate 1
  • Name: eMudhra Technologies Limited
  • Alias name: emsignrootcag1
  • Distinguished name: CN=emSign Root CA - G1, O=eMudhra Technologies Limited, OU=emSign PKI, C=IN
Certificate 2
  • Name: eMudhra Technologies Limited
  • Alias name: emsigneccrootcag3
  • Distinguished name: CN=emSign ECC Root CA - G3, O=eMudhra Technologies Limited, OU=emSign PKI, C=IN
Certificate 3
  • Name: eMudhra Technologies Limited
  • Alias name: emsignrootcag2
  • Distinguished name: CN=emSign Root CA - G2, O=eMudhra Technologies Limited, OU=emSign PKI, C=IN

See JDK-8319187 (JDK Bug System).

Telia Root CA v2 certificate added

In Red Hat build of OpenJDK 17.0.10, the cacerts truststore includes the Telia Root CA v2 certificate:

  • Name: Telia Root CA v2
  • Alias name: teliarootcav2
  • Distinguished name: CN=Telia Root CA v2, O=Telia Finland Oyj, C=FI

See JDK-8317373 (JDK Bug System).