CAS-002 · Question #157
A data processing server uses a Linux based file system to remotely mount physical disks on a shared SAN. The server administrator reports problems related to processing of files where the file…
The correct answer is D. The Linux file system in use cannot write files as fast as they can be read by the Java. The symptoms describe files being read before they are fully written to disk. Millions of small files are being written sequentially from a network source; if the Java program reads files faster than the Linux file system can write them (due to I/O throughput differences…
Question
A data processing server uses a Linux based file system to remotely mount physical disks on a shared SAN. The server administrator reports problems related to processing of files where the file appears to be incompletely written to the disk. The network administration team has conducted a thorough review of all network infrastructure and devices and found everything running at optimal performance. Other SAN customers are unaffected. The data being processed consists of millions of small files being written to disk from a network source one file at a time. These files are then accessed by a local Java program for processing before being transferred over the network to a SE Linux host for processing. Which of the following is the MOST likely cause of the processing problem?
Options
- AThe administrator has a PERL script running which disrupts the NIC by restarting the
- BThe Java developers accounted for network latency only for the read portion of the
- CThe virtual file system on the SAN is experiencing a race condition between the reads and
- DThe Linux file system in use cannot write files as fast as they can be read by the Java
How the community answered
(43 responses)- A23% (10)
- B5% (2)
- C12% (5)
- D60% (26)
Explanation
The symptoms describe files being read before they are fully written to disk. Millions of small files are being written sequentially from a network source; if the Java program reads files faster than the Linux file system can write them (due to I/O throughput differences between network write speed and local Java read speed), the Java program may access and process partially written files - resulting in incomplete data. The network has been ruled out, and other SAN customers are unaffected (ruling out SAN-wide issues). Option A (PERL script disrupting NIC) is speculative and unsubstantiated. Option B (network latency for reads) is ruled out by the network team. Option C (race condition at the SAN level) is less likely since other SAN clients are unaffected.
Topics
Community Discussion
No community discussion yet for this question.