Briefly, this error occurs when Elasticsearch is unable to resolve the local host’s IP address and defaults to the loopback address (127.0.0.1). This could be due to network issues, incorrect configuration, or DNS resolution problems. To resolve this, ensure your network is functioning properly, check your Elasticsearch configuration for any errors, and verify that your DNS server is correctly resolving hostnames. If the issue persists, you may need to manually specify the network host in the Elasticsearch configuration file.
This guide will help you check for common problems that cause the log ” failed to resolve local host; fallback to loopback ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: network.
Log Context
Log “failed to resolve local host; fallback to loopback” classname is NetworkUtils.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
static {
InetAddress localAddressX;
try {
localAddressX = InetAddress.getLocalHost();
} catch (Throwable e) {
logger.warn("failed to resolve local host; fallback to loopback"; e);
localAddressX = InetAddress.getLoopbackAddress();
}
localAddress = localAddressX;
}
