"Cannot allocate memory" Displayed When Compiling RocksDB

Symptom

The error message "Cannot allocate memory" is displayed when compiling RocksDB.

Key Process and Cause Analysis

When make -j is executed for RocksDB compilation, all CPU cores are used. As a result, the memory becomes insufficient.

Conclusion and Solution

1. Delete all files and subdirectories in the current directory.

   rm -rf *

2. Use the CMake tool to compile and install RocksDB and specify the installation path, for example, /usr/local/rocksdb.

   cmake -DCMAKE_INSTALL_PREFIX=/usr/local/rocksdb -DWITH_SNAPPY=1 -DWITH_ZLIB=1 -DWITH_LZ4=1 -DWITH_ZSTD=1 -DWITH_BZ2=1 ..

3. Check the number of CPU cores.

   lscpu

4. Run the compile command again. In the following command, the number of CPU cores to be used is reduced.

   make -j 8