[ABSTRAK
Arsitektur jaringan overlay P2P berjenjang terstruktur (structuredhierarchical P2P) sangat sesuai untuk jaringan heterogen karenamempertimbangkan keberagaman kapabilitas peer. Pada penelitian ini diusulkanpendekatan baru mekanisme rejoin yang dinamakan collective rejoin, dimanaproses rejoin dilakukan secara per kelompok, sebagai alternatif dari pendekatanindividual rejoin yang selama ini diterapkan pada arsitektur P2P berjenjangterstruktur berbasis Chord. Setiap kelompok yang mengalami kegagalansuperpeer akan menunjuk normal peer dengan kapabilitas tertinggi dalamkelompoknya sebagai superpeer baru. Superpeer baru ini yang akan mengirimkanpesan rejoin ke sistem. Dengan pendekatan ini, jumlah trafik rejoin akan jauhberkurang dibandingkan pendekatan individual rejoin, sehingga konsumsibandwidth untuk overhead trafik pengelolaan dapat dikurangi.Kinerja pendekatan collective rejoin ini dievaluasi dengan menggunakanparameter: variasi nilai rasio superpeer, tingkat dinamika jaringan (churn), ukuranjaringan, dan tingkat kesibukan jaringan (lookup query rate). Evaluasi kinerjadilakukan dengan mengamati jumlah trafik yang dihasilkan oleh proses rejoinpada saat terjadi kegagalan superpeer (rejoin traffic load), rasio antara lookupquery yang berhasil diselesaikan terhadap seluruh lookup query yang terjadi(successful lookup rate), dan banyaknya hop yang harus ditempuh untukmenyelesaikan sebuah lookup query (lookup query cost). Nilai efisiensi diperolehberdasarkan penghitungan penghematan penggunaan bandwitdh yang dapatdilakukan oleh pendekatan collective rejoin.Pada seluruh parameter yang diujikan, pendekatan collective rejoinmenghasilkan jumlah trafik rejoin yang lebih sedikit dibandingkan denganpendekatan individual rejoin. Hal ini dibarengi juga dengan successful lookup rateyang rata-rata lebih baik, dengan tanpa meningkatkan lookup query cost. Rasiosuperpeer dan ukuran jaringan berpengaruh signifikan terhadap nilai efisiensi.Sedangkan pada pengujian terhadap parameter tingkat dinamika jaringan dantingkat kesibukan jaringan, nilai efisiensi relatif tetap. Hasil simulasimenunjukkan bahwa pendekatan collective rejoin efektif jika diterapkan padajaringan P2P berjenjang terstruktur dengan ukuran kelompok yang besar (padapenelitian ini, dengan rasio superpeer terbesar adalah 10%).;

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ABSTRACT
By considering the diversity of poverlay network architecture is weeer capability, structured hierarchical P2Pll suited for heterogeneous networks. In thisresearch, a new approach of rejoin mechanism is proposed, called collectiverejoin, whereby rejoin process is done per group. Each group that experiences asuperpeer failure will appoint a normal peer that has highest capabilities in thegroup as the group's new superpeer. This new superpeer will send rejoin messageto the system. Using this approach, the number of rejoin traffic is less thanindividual rejoin. In turn, it will decrease the bandwidth consumption ofmanagement traffic overheadThe collective rejoin approach performance is evaluated using parameters:variety of superpeer ratio, network dynamics level (churn), network size, andoverlay network activities level (lookup query rate). Performance evaluation isconducted by observing the number of rejoin traffic, the successful lookup rate,and the lookup query cost. The efficiency value is obtained by calculatingbandwidth consumption saving by the collective rejoin approach.On all tested parameters, the collective rejoin approach produces fewerrejoin traffics than the individual rejoin approach. The successful lookup rate ofcollective rejoin is outperform the individual rejoin. The lookup query cost of thecollective rejoin can be maintained at the same value as in the individual rejoin.Superpeer ratio and network size significantly impact the efficiency. Meanwhile,networks dynamic and activities provide a relative stable efficiency. The resultsshow that the collective rejoin approach is useful for large group size hierarchicalstructured P2P (in this research the maximum superpeer ratio is 10%).;By considering the diversity of poverlay network architecture is weeer capability, structured hierarchical P2Pll suited for heterogeneous networks. In thisresearch, a new approach of rejoin mechanism is proposed, called collectiverejoin, whereby rejoin process is done per group. Each group that experiences asuperpeer failure will appoint a normal peer that has highest capabilities in thegroup as the group's new superpeer. This new superpeer will send rejoin messageto the system. Using this approach, the number of rejoin traffic is less thanindividual rejoin. In turn, it will decrease the bandwidth consumption ofmanagement traffic overheadThe collective rejoin approach performance is evaluated using parameters:variety of superpeer ratio, network dynamics level (churn), network size, andoverlay network activities level (lookup query rate). Performance evaluation isconducted by observing the number of rejoin traffic, the successful lookup rate,and the lookup query cost. The efficiency value is obtained by calculatingbandwidth consumption saving by the collective rejoin approach.On all tested parameters, the collective rejoin approach produces fewerrejoin traffics than the individual rejoin approach. The successful lookup rate ofcollective rejoin is outperform the individual rejoin. The lookup query cost of thecollective rejoin can be maintained at the same value as in the individual rejoin.Superpeer ratio and network size significantly impact the efficiency. Meanwhile,networks dynamic and activities provide a relative stable efficiency. The resultsshow that the collective rejoin approach is useful for large group size hierarchicalstructured P2P (in this research the maximum superpeer ratio is 10%)., By considering the diversity of poverlay network architecture is weeer capability, structured hierarchical P2Pll suited for heterogeneous networks. In thisresearch, a new approach of rejoin mechanism is proposed, called collectiverejoin, whereby rejoin process is done per group. Each group that experiences asuperpeer failure will appoint a normal peer that has highest capabilities in thegroup as the group's new superpeer. This new superpeer will send rejoin messageto the system. Using this approach, the number of rejoin traffic is less thanindividual rejoin. In turn, it will decrease the bandwidth consumption ofmanagement traffic overheadThe collective rejoin approach performance is evaluated using parameters:variety of superpeer ratio, network dynamics level (churn), network size, andoverlay network activities level (lookup query rate). Performance evaluation isconducted by observing the number of rejoin traffic, the successful lookup rate,and the lookup query cost. The efficiency value is obtained by calculatingbandwidth consumption saving by the collective rejoin approach.On all tested parameters, the collective rejoin approach produces fewerrejoin traffics than the individual rejoin approach. The successful lookup rate ofcollective rejoin is outperform the individual rejoin. The lookup query cost of thecollective rejoin can be maintained at the same value as in the individual rejoin.Superpeer ratio and network size significantly impact the efficiency. Meanwhile,networks dynamic and activities provide a relative stable efficiency. The resultsshow that the collective rejoin approach is useful for large group size hierarchicalstructured P2P (in this research the maximum superpeer ratio is 10%).]