Deadlock detection in multidatabase systems: a performance analysis

Towards an efficient probabilistic deadlock detection method for multidatabase systems

“…This probabilistic analysis result is important, since it confirms the experiments (simulation) results obtained recently by [4]. In this work, where MDBS are assumed to be with symmetrical structure, it is observed that the distribution of potential deadlock cycle length in the PCG, is very skewed, and almost Moreover, this probabilistic analysis of the PCG justify and enforces the interest of deadlock detection strategies which concentrate on the analysis of potential global deadlocks involving no more than 4 GTs (sites) that we called 4-PCG.…”

“…In the other hand when the local workload is light then real deadlock correspond especially to cycle in the PCG of length two as it is observed in [4]. In the future work, we attempt to give an accurate evaluation of q allowing to evaluate the performance of such probabilistic deadlock detection method.…”

“…When an active transaction requests a local lock and it does no abtain it, it's status changes from active to waiting. 4 Probabilistic Analysis of the PCG We want to point that the use of informations provided by the PCG (cycles) is of great interest for any deadlock detection method since these informations help to reduce the number of unnacessary GTs aborts. However, the performance of an algorithm based on PCG can be affected by the great number of apparent deadlocks, i.e.…”

“…In this work, where MDBS are assumed to be with symmetrical structure, it is observed that the distribution of potential deadlock cycle length in the PCG, is very skewed, and almost Moreover, this probabilistic analysis of the PCG justify and enforces the interest of deadlock detection strategies which concentrate on the analysis of potential global deadlocks involving no more than 4 GTs (sites) that we called 4-PCG. In [4] it is proposed a such algorithm called HDD (2-PCG ); where the detection on PCG is restricted to potential global deadlock involving two transactions.…”

“…If we consider probability equal to 1 as [4], then due to theoreml, any method based on 2, 3 or 4-PCG has practically the same performance than any algorithm using the entire PCG.…”