Testing of lock managers in computing environments

• US 10,614,039 B2
• Filed: 04/04/2017
• Issued: 04/07/2020
• Est. Priority Date: 04/04/2017
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Davis, Willard A., Davis, James C.
• Primary Examiner(s): Richardson, James E
• Application Number:
  US15/478,675
• Publication Number:
  US 20180285380A1
• Time in Patent Office: 1,099 Days
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/1774 Locking methods, e.g. locking methods for file systems allowing shared and concurrent access to files
• CPC Class Codes: G06F 16/182 Distributed file systems
• CPC Class Codes: G06F 16/1858 Parallel file systems, i.e. file systems supporting multiple processors
• CPC Class Codes: G06F 16/2343 Locking methods, e.g. distributed locking or locking implementation details
• CPC Class Codes: G06F 16/2365 Ensuring data consistency and integrity

Abstract

A lock manager configured for locking files is tested. As part of the test and based on a lock assignment plan, a process acquires locks on portions of the files. Based on a lock testing plan, a second process performs a lock verification for a portion of the locked portions. A result of this lock verification is compared to its expected result. Based on an updated lock assignment plan, the process transitions from the locks to other locks on other portions of the files. Based on an updated lock testing plan, the second process performs a second lock verification for a portion of the other locked portions. A result of this second lock verification is compared to its expected result. Based at least in part on the two comparisons, the lock manager is evaluated.

Claims

1. A system for testing a locking mechanism, the system comprising:

at least one memory; and

at least one processor in communication with the at least one memory, the at least one processor configured to obtain instructions from the memory that cause the at least one processor to perform a method comprising;

distributing, among a plurality of processes, lock assignment information for a set of files;

acquiring, based on the distributed lock assignment information and by a first process of the plurality of processes, a lock on a first portion of the set of files;

acquiring, based on the distributed lock assignment information and by a second process of the plurality of processes, a lock on a second portion of the set of files;

distributing, among the plurality of processes, lock testing information for the set of files;

attempting, based on the distributed lock testing information and by the first process, to acquire a lock on the second portion;

comparing a result of the attempted lock and an expected result of the attempted lock; and

evaluating, based at least in part on the comparing, the locking mechanism, wherein the method further comprises;

distributing, among the plurality of processes, second lock assignment information for the set of files;

determining, by the first process and using the first portion as an input into an update algorithm included in the distributed second lock assignment information, that a lock is to be acquired on a third portion of the set of files, wherein the update algorithm is configured to output that the lock on the third portion is a next lock to be acquired by the first process after relinquishing the lock on the first portion based on the fact that first process currently has the lock on the first portion;

relinquishing, by the first process and based on the update algorithm, the lock on the first portion; and

acquiring, by the first process and based on the determination, the lock on the third portion after the relinquishment of the lock on the first portion.

2. The system of claim 1, wherein the method further comprises:

determining, by the second process and using the second portion as an input into a second update algorithm included in the distributed second lock assignment information, that a lock is to be acquired on a fourth portion of the set of files;

relinquishing, by the second process and based on the second update algorithm, the lock on the second portion; and

acquiring, by the second process and based on the determination that the lock is to be acquired on the fourth portion, the lock on the fourth portion.

3. The system of claim 1, wherein the method further comprises:

determining, by the first process and based on a tiebreaker algorithm included in the distributed second lock assignment information, the tiebreaker algorithm configured to avoid conflicting lock acquisition attempts among the plurality of processes, not to acquire a lock on a fourth portion of the set of files.

4. A computer program product for iteratively testing a lock manager configured for locking a set of files stored in a file system, the computer program product comprising a computer readable storage medium, the computer readable storage medium having program instructions embodied therewith, the programs instructions configured, when executed by at least one computer, to cause the at least one computer to perform a method, the method comprising:

acquiring, based on a lock assignment plan and by a first process of a plurality of processes, a first plurality of locks on a first plurality of portions of the set of files;

performing, based on a lock testing plan and by a second process of the plurality of processes, a first lock verification for a first portion of the plurality of portions;

comparing a first result of the first lock verification and a first expected result of the first lock verification;

transitioning, based on an updated lock assignment plan and by the first process, from the first plurality of locks to a second plurality of locks on a second plurality of portions of the set of files, wherein the transitioning comprises;

determining, by the first process and using the first plurality of portions as inputs into an update algorithm incorporated in the updated lock assignment plan, that the second plurality of locks are to be acquired on the second plurality of portions;

relinquishing, by the first process and based on the update algorithm, the first plurality of locks; and

acquiring, by the first process and based on the determination, the second plurality of locks;

performing, based on an updated lock testing plan and by the second process, a second lock verification for a second portion of the second plurality of portions;

comparing a second result of the second lock verification and a second expected result of the second lock verification;

acquiring, based on the lock assignment plan and by a third process of a plurality of processes, a third plurality of locks on a third plurality of portions of the set of files;

transitioning, based on the updated lock assignment plan and by the third process, from the third plurality of locks to a fourth plurality of locks on a fourth plurality of portions of the set of files, wherein the transitioning from the third plurality of locks to the fourth plurality of locks comprises;

determining, by the third process and using the third plurality of portions as inputs into a second update algorithm incorporated in the updated lock assignment plan, that the fourth plurality of locks are to be acquired on the fourth plurality of portions;

relinquishing, by the third process and based on the second update algorithm, the third plurality of locks; and

acquiring, by the third process and based on the determination that the fourth plurality of locks are to be acquired, the fourth plurality of locks; and

evaluating, based at least in part on the comparing the first result and first expected result and the comparing the second result and the second expected result, the lock manager, wherein the update algorithm is a Simple Up update algorithm and the second update algorithm is a Greedy Down update algorithm.

5. The computer program product of claim 4, wherein the performing the first lock verification comprises:

querying, based on the lock testing plan and by the second process, the lock manager as to whether or not a read lock is currently obtainable for the first portion.

6. The computer program product of claim 5, wherein the performing the first lock verification further comprises:

querying, based on the lock testing plan and by the second process, the lock manager as to whether or not a write lock is currently obtainable for the first portion.