Why Does a Client Keep Failing to Connect to a Server for a Long Time?

Question

A HBase server is faulty and cannot provide services. In this case, when a table operation is performed on the HBase client, why is the operation suspended and no response is received for a long time?

Answer

Problem Analysis

When the HBase server malfunctions, the table operation request from the HBase client is tried for several times and times out. The default timeout value is Integer.MAX_VALUE (2147483647 ms). The table operation request is retired constantly during such a long period of time and is suspended at last.

Solution

The HBase client provides two configuration items to configure the retry and timeout of the client. Table 1 describes them.

Set the following parameters in the Client installation path/HBase/hbase/conf/hbase-site.xml configuration file:

Figure 1 describes the working principles of retry and timeout.

Figure 1 Process for HBase client operation retry timeout

The process indicates that a suspension occurs if the preceding parameters are not configured based on site requirements. It is recommended that a proper timeout period be set based on scenarios. If the operation takes a long time, set a long timeout period. If the operation takes a shot time, set a short timeout period. The number of retries can be set to (hbase.client.retries.number)*60*1000(ms). The timeout period can be slightly greater than hbase.client.operation.timeout.