Launching reaper String join – How to solve this OpenSearch error

Opster Team

Aug-23, Version: 1-2.9

Before you dig into reading this guide, have you tried asking OpsGPT what this log means? You’ll receive a customized analysis of your log.

Try OpsGPT now for step-by-step guidance and tailored insights into your OpenSearch operation.

Briefly, this error occurs when the OpenSearch system attempts to initiate a reaper process but encounters an issue with the string joining operation. This could be due to incorrect syntax, null values, or incompatible data types. To resolve this, you should first check the syntax of the String.join operation to ensure it’s correct. Next, verify the values being joined are not null and are of a compatible data type. If the issue persists, consider debugging the code to identify the exact point of failure.

For a complete solution to your to your search operation, try for free AutoOps for Elasticsearch & OpenSearch . With AutoOps and Opster’s proactive support, you don’t have to worry about your search operation – we take charge of it. Get improved performance & stability with less hardware.

This guide will help you check for common problems that cause the log ” Launching reaper: ” + String.join(” ” to appear. To understand the issues related to this log, read the explanation below about the following OpenSearch concepts: .

Log Context

Log “Launching reaper: ” + String.join(” ” classname is
We extracted the following from OpenSearch source code for those seeking an in-depth context :

                    "-Xmx16m"; // no need for a big heap; just need to read some files and execute
      "Launching reaper: " + String.join(" "; builder.command()));
                // be explicit for stdin; we use closing of the pipe to signal shutdown to the reaper
                reaperProcess = builder.start();


How helpful was this guide?

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Get expert answers on Elasticsearch/OpenSearch